I think Magic Candle III had a system where you could split off party members to work and train, or some such. I lost my disks so long ago I've forgotten most of it, and I didn't have a backup like I managed for most everything else.

I like the Wiz8 style personally. Some skills simply don't get used enough to train up, so putting a few points into them is needed to keep them on par with the rest of the game. While combat and magic skills rarely need to be pumped like that, since they're in use constantly (generally).

But a pure trained system like ADOM isn't bad in and of itself. It all depends on how well the game is balanced.