Yeah, it's really hard to deduce what component from Avatar procs made melees complete monsters in PvP, but atk power was probably the most significant thing to change when it did proc.
I thought atk power made it so that hits you do connect with become more consistently top end, but if hit rate% is calculated from that too, I don't know.
http://everquest.allakhazam.com/wiki/EQ:Stats
It sounds like from this, Strength is the only thing that directly effects hit rate % on normal auto attacks. Dex hit rate is apparently only in relation to special abilities (Flying Kick, Backstab, etc.) and proc rates. Hit rate % calculated by strength sounds more reasonable. That was probably the reason Ogres and Trolls were considered the best during this era. There was no real way to max the really important combat stats during this era without being either one of those two races.
Though with the current amount of gear in Kunark, lots of people are able to max strength with buffs, so we might see the same ordeal even if it were changed. It just seems like the hit rate in PvP is absurd. Well geared Enchanters could chain rune through damage on live, Shamans could tank with Torpor on - but here, if a melee even gets close to me, I bounce. It's just too dangerous being anywhere close to them.