This discussion is really interesting, the match up against FEC is important in the actual meta, this army is top tier (maybe god tier before FAQ).
So learning to play against them is important to consider (like the new skaven).
I never played against them yet, but it will come and i'm a bit afraid, MW output, mobility, summons...
My actual list is squig oriented
Skargrott as general
Loonboss on Mangler Squigs
Loonboss on Giant Squig
Fungoid Cave Shaman
12 Squig Herd
12 Squig Herd
20 stabbas
10 Boingrot Bounderz
10 Boingrot Bounderz
10 Boingrot Bounderz
Squig Rider Stampede
Mork's Mighty Mushroom
Scarpskuttle's Arachnacauldron
2000/2000
The most important thing in my mind is how to prevent Terrorgeist and / or Flayers to charge your Bounderz first and snipe the Archregent and / or others characters who can summon