Well i never played top tier army wfb/aos alike as my main army were mostly chd. I agree with you that i would prefere that gw should release balanced books. But when you play in highly competetive enviroment and see half of the ppl play dok/fec/skaven/slaneesh/cos armies that can charge you first turn,destroy you in magic turn, shooting, summon etc you start to think "how nice it would be on the tip from time to time"