I would put them at the high end of the middle of the pack.
Probable something like this:
Tier 1: WoC, Dark Elves, Empire
Tier 2: Vampires, Ogres, Lizards, High Elves
Tier 3: Dwarfs, Skaven, Brettonians
Tier 4: Orcs and Goblins, Daemons, Tomb Kings
Tier 5: Beastmen, Wood Elves
Some could go up or down a bit, but this is what I would put everything at overall.
Empire, Warriors, and Dark elves are incredibly powerful with their new books.
Ogres, Vampires, and High elves are good, but they are more one dimensional in terms of what lists are going to be successful, which means they are more likely to drop games than those in Tier 1. Lizardmen have a huge amount of flexibility in the army now, and most of their units became stronger/cheaper in one way or another, so they are going to be consistent in performance with a competitive list, though they are unlikely to win all 5 of their games due to struggles with certain things.
Dwarfs are slow, and most of their combat units are not quite up to par, though their artillery and magic defense are unmatched. Skaven are incredibly unreliable, and Brettonians are 1 dimensional as above, but slightly weaker about it due to not being able to put a lot of mass into their army and their magic limitations.
Orcs and Goblins, are competitive, but animosity is likely to cause even the best list to drop games, and they are limited in terms of magic and shooting, and most of their best units are frenzied or stupid.
Daemons; way too random to perform consistently. likely the army will lose the game on its own at least once a tournament.
Tomb Kings: Though they can make a competitive army, no matter what they do, their combat will be sub par, and they will struggle to deal with tough infantry.
Beastmen and Wood elves are just not up to par.
Beastmen can make good lists, but they are predictable, and inconsistent due to over-reliance on certain phases.