i do have the unofficial 3rd edition Historical KoW rules, which i guess is more army lists than rules, but i havent had a chance to try them out yet, but i have tried Hail Caesar rules, which i like as an alternative to KoW. A lot of my local gamers are into 6th edition Warhammer, but everytime i play it, I come up against armies that are not in the slightest bit balanced.
Generally, Kings of War is fairly balanced with each army getting some naff shooty units, some sort of Giant, something that can fly, a bit of chaff and some expensive elite heavy infantry type of units etc. and generally the rules make sense. I understand critics of the corkscrew like charges that can be pulled off, (i haven’t played with the new rules yet, so they might have fixed that) but i’m more than happy to embrace a club rule that stops that.