Here's the 2018 Matchups list as i see it, I'll be updating as the year unfolds.
Idoneth Deepkin - Neutral
Look man I dunno. This army is just weird. We wreck their infantry with sickening ease but the eels are annoying. Their magic is good and the Ishraan Rites are pretty non interactive. The big turtle thing goes down like a sack of cheap seafood but they never take it so it's irrelevant. Stay away from the shipwrecks, kill the support heroes. And on the High Tide they'll wreck us so retreat away or prepare for it with buffs like Rabid Fever.
Daughters of Khaine - Neutral
You know that image of the two spidermen pointing at each other? This is gonna feel a lot like that. A prayer based army that uses cheap, low survivability infantry taken in large numbers with hero support to charge across the table and try and sweep the opponent away while being supported by close range war machines, low reliability shooting and a single large hero character who forms the lynchpin of the force. Was I describing us or them? Doesn't matter. Target blobs of infantry with Plagueclaws and dump the Plague Spell on them. Form a line of Plague Monks to catch the Witch Aelves and buff em up with Rabid Fever and Bless with Filth.
Maggotkin of Nurgle - Major Advantage to Clan Pestilens
LOL this one almost feels unfair. Half of their spells and AOE damage effects can't even affect you due to Pestilens also having the NURGLE keyword. Their vulnerability is massive amounts of attacks to combat their saves, and that's our whole thing. These two things are enough to tilt the balance towards us, but there is one last itsy bitsy detail. That buff wheel they get to work through each turn? All nurgle units. Not THEIR nurgle units. ALL nurgle units. Laugh at them and drink their tears.
Blades of Khorne - Minor Advantage to Blades of Khorne
A combat based army, and a good one. Ordinarily Pestilens will blenderize anything that fancies itself a combat favoring army but these guys are a little different. They have a massive range of options, we have 6 models all up. The build paths open to them let them be MORE than a combat army, something Pestilens can't actually do. Essentially it boils down to who hits who first. This is one the few matchups were Plagueclaws are actually good due to the favoribility of Bloodletter Bombs and Bloodreaver Hordes. Overall you want to be the one who gets the first charge off and make sure your units have the Furnace prayer that lets them fight one dead, you'll need it.
Disciples of Tzeentch - Major Advantage to Disciples of Tzeentch
Lol don't even get me started, the weakness of Clan Pestilens is no ability to deal with long range and movement shenanigans. Run up, charge to get closer to objectives and pray you can last longer than they can throw spells. Skyfires are the devil, Horrors are just annoying and the Gaunt Summoner will quite literally light you on fire and roast marshmellows on the corpse. The best strategy when facing Tzeentch with Pestilens is to either avoid it or whine about balance in chat groups. Take an Arch Warlock with a Balewind and try play them at their own game, but ultimately this one is a little skewed.
Sylvaneth - Minor Advantage to Clan Pestilens
This one used to feel on par with Disciples of Tzeentch until playing them a bit more, and of course the meta no longer favoring Kurnoth with bows. The trick is to take the field before they take the field, by any means necessary. Run in the first movement phase, charge anything within reach if you went second, do anything you can to get in their face. They put wildwoods in front of you? ****** em, run straight through it. Charge through it ideally. If you think the Dangerous Terrain effect is something to be afraid of, you are a coward or too considerate of your rat's lives, and neither of these traits are found in good Pestilens players. Get on top of 2 or so objectives and refuse to leave like a disenfranchised family member on Christmas, and god willing victory shall be yours. In a perfect world they'll run lots of Revenants over dryads and you drown them in dice, asking your opponent with a smug smile if he'd like to use Martial Memories to reroll one of the failed 30 saves.
Kharadron Overlords - Neutral
This is a weird one. Kharadron Overlords are dwarves, but only in the sense that they're short. They aren't slow, they aren't sturdy and their beards are a solid source of iron intake. Kharadron are like life, they come at you hard and fast. This is sometimes a good thing, sometimes terrible. So basically, what it comes down to is if the Overlord player invested in weight of shots (good for you) or they invested in high damage weapons like Drill Cannons (You're screwed). With weight of shots they can't actually kill enough rats for it to matter before they're on the recieving end of a plague monk charge, and oddly despite those boats being in the sky we can still smack them back down. Surround the boat and they can't deploy it's contents, which is even better. However with the Drill Cannons and so on we lose our Plague Furnaces on turn 2, Corruptor turn 3, and the game shortly after. Their weakness is the terrible range of pretty much all shooting that isn;t on a Thunderer or Ironclad, ours is they actually have guns. Play the objectives and bait them into range.
Flesh Eater Courts - Major Advantage to Clan Pestilens
This one is fun. They have no shooting, and they want to be in close combat. Naysayers would say "but Aiden, they can bring back their troops and we can't!". To that i say, ever seen Ghouls put out 40 wounds + several mortal wounds before saves are made? Probably not. Yeah Ghouls can regnerate lost troops, but only when a nearby Courtier does it for them. A wee, little Courtier with a weak save and fewer wounds. Slash him down to size with prayer spam. Flesh Eater Courts are an infantry spam buff army, just like Clan Pestilens, we just happen to be WAY better at it than they are. Butcher what they throw at you and take the field, if their characters get wise deal with them by throwing a Plague Furnace their way.
Ironjaws - Minor Advantage to Clan Pestilens
Ironjaws are a semi-elite army that don't put out massive damage but make up for it by being relatively tricky to kill. This is the matchup where discretion is the better part of valor for Pestilens. Try and go around them to get to objectives, don't hesitate to retreat if it means snaking behind them to get where you need to go. Multiwound infantry means no half measures, if you engage them engage them with all possible force and sweep them aside. Time spent fighting them is time wasted and that's what they want. Use prayers to make sure your monks can easily wound and trigger dice roll of 6 or more effects, don't waste time trying to d3 mortal wounds them to death it takes way too long.
Bonesplitterz - Major Advantage to Bonesplitterz
Interestingly this is an easy game really if they don't take Kunnun Rukk. Jokes on you however, they pretty much always do. Theyre surprisinly resilient and tying them up in combat doesn't stop them shooting you. And dear god will they shoot you, again and again and again. It's like facing the easier to batch paint version of Free Peoples. Try and kill the leaders to stop the batallions workind and take a Plaguesmog with Vexlers Shroud on the Furnace so it's -2 to hit. Thats basically all the counterplay there is here.
Stormcast Eternals - Minor Advantage to Pestilens
The boys in gold, a very diverse force with a lot of options. If we assess Stormcast at their base weaknesses, which is having to deal with weight of numbers and mortal wounds, we have a clear and easy advantage. If they play Vanguard and keep running away and shooting us it's a bit harder. If they play Aetherstrike it's an uphill footslog through the shittiest parts of Chernobyl. Play the game to the objectives, take the table to prevent Borne by the Storm and Lightning Chariot and do your best to retain your high numbers.
Fireslayers - Major Advantage to Fireslayers
If they're smart and take a bucketload of Vulkites you'll drown in them. If you can get around that or maybe pepper them with Plagueclaws it will be ok and you'll pull an objective victory. Magmadroths are terrible, 20 plague monks will wipe one out easily. They can't get their axes into range (unless under runic effect) without coming into charge range so bear that in mind. They're hard to shift, and they'll outlast you ten times out of ten. Avoid getting bogged down and charge the less defensive stuff like Auric Bezerkers and Hearthguard, and for the love of god stay away from the Grimrath Bezerker.
Seraphon - Minor Advantage to Seraphon
Our mortal foes, the artist formerly known as Lizardmen. Their strengths are defense against rend, their weakness is mortal wounds, so you might think, where is their advantage. Lords of Space and TIme. They can retreat across the table without it even being a retreat, dump a line of Saurus Guard in our way, and abuse long range magic which we can;t really unbind, as well as unbinding any few attempts we make at casting. Also the Verminlord is a Chaos Daemon which they specifically do well against.
Comment what more you'd like to see, fellow Pestilens player.