If you want for fun i can give you my opinion:
T1\overpower tier\broken tier\need huge nerfs in warscrolls and points:
-osiar bonereapers:it is beyond me and everyone that i speak as a army can have a 100% free and with no counterplay +1 save,also this army is broken due to stacks of buffs,+1 save free,4 special save(6 from close to hero,+1 with upgraded version of relik,+1 with a spell),reroll all saves,models wont die with a 4+ and then revive models also. Have models with a save of 3 rerolling all faills,with a special save of 4 and THEN if die can come back with a 4+ and even if all this faill katakros gonna bring them back again,is STUPID
-slanesh: two words:free sumon. When a model can bring his cost or more back to the table as free sumon we have a balance problem,also the allways attack first is stupid broken
T2\overpower armys that need points nerfs
-dok:wyches are undercosted yet and the free 6 special save need nerf
-big wag: it is new but people allready are seeing how broken it is,have free with 0 counterplay a +1 save+1 hit+1 wound armywide only dont spending wag is broken and need be nerfed
-flesh eater:heroes that can sumon units that cost 80% of the hero cost is umbalanced
-skaven:need more points nerfs as all is too much underpriced in specialverminlords need cost 60 more points to start to be close to balanced
-death:legion of nagash\grif etc etc: free sumon is umbalanced period
-tzenth:new tome have bring the stupid build of horrors for 200 points having 999999999 wounds with free sumon,and also a armywide -1 to be hit in melle is broken
-slaves to dsrkness: the chaos sorcerer lord with a cost of 110 when have a castellant ability(120points) + the loremaster upgraded buff(120) is stupid and need cost 200 points to be close to balanced, also every unit is good and with the new alegiance buffs are underpriced as the +1 wound from khorne
T3:balanced armys
-fyreslayers:for me vulkites need cost 120 points, rangued elites need be cheaper,magmadroths need a special save and heartguard zerkers could use a 20 points nerf
-idoneths:all is playable(even if idoneths players cry about tralls) and good and that it is being a late 1.0\first 2.0 tome
-kharadrons: a but too much overcosted but with good movility
-blades of khorne
-nurgle
-city of sigmar:every dwarf unit need a 20 points reduction and some unit as phoenyx guard could use a increase
-ogors: are fast,durable and great at melle
-seraphons:with free sumon they are very good but without it are mediocre
-stormcast:new sacrosant chamber is very good,edtremis is good,vanguard chapter is underpower and vanilla chamber overcosted
-silvaneth:with alariele free sumon and new tree buffs they are great
-nigthaunt: great army
- glomspite: overall a great army that could be in t2 but due to how random arent reliably
Under this tier are other armys that need buffs and i didnt said nothing or some builds of those armys as stormcast with vanguard chapter or city of sigmar with only dwarfs that are in boton tiers with need of buffs
This is only my opinion,the tournament data are show in that link and are acurate