The only problem I have with a lot of different weapon types is that after you pass about 12 separate types or so, it starts getting harder to find one specific weapon type. The more weapon types, the harder it is to balance them.

I think the way Divinity 2 handled masteries (one handed, one handed + shield, dual wielding, two handed) was better than Divine Divinity's 6 or so masteries, one for each type (sword, axe, mace). Divinity 2 did only have one type of two-handed weapons, swords - no 2H axes or warhammers.

Just keep in mind that there can be too much of a good thing.