I've been playing Co8 v5.0.5 ToEE. In my current game I have a Ranger/Rogue who is dual-wielding a couple of Great Cleavers. Today I found that I had not figured out the weapon as I thought I had. After some testing and looking around on a couple of sites, I found that the Great Cleaver is considered a hand axe for purposes of Focus and Specialization, which makes sense considering what a cleaver is. But to my dismay, it is not considered a hand axe by the game's mechanics when it comes to the Weapon Finesse feat. The hand axe is considered a light weapon and gets the benefit of Weapon Finesse, yet the Cleaver does not. Is this a bug, or is it intentional? I had hoped to have a decent attack score with it after taking the Finesse feat, especially since my character is dual-wielding them, but no dice. I wasted two feats. Or at least one no matter which way I go. If I switch to shortswords, I get my attack bonus, but my Weapon Focus in hand axes is useless. I really don't care for wielding two normal hand axes who's crit is only on a natural 20. Also, I found take a -4/-4 penalty with two Cleavers. When you consider that, I guess it qualifies more like the rapier that is not a light weapon, but does work with Finesse. I guess for now I'll just give my character's things to another party member, drop him at the inn's registry, or kill him off, then add a new version of him, hex edit his exp to match the old character's total, and re-level him.
Pretty sure it's intentional. While a handaxe is size_small (and thus finessable) the cleavers are medium, and as far as I know, the only medium weapon that can be used with weapon finesse or used as a light offhand is the rapier. I once had a fighter who dual wielded those - the aesthetic value was worth the negatives.
Yeah, I've gone dual-wield with cleavers, but that was a strong ranger not a finessing rogue. They're medium weapons, ergo it all makes sense.