However you balance and juggle it, the entire attribute system is a sham.
The only thing that it governs is your DPS, and so there's no real depth or strategy to it. It's not that it can help you make an interesting character with strengths and weaknesses.
If you go wizard there's no reason not to put everything in INT, ever. Even if you DO take combat skills you'll be shit with them as the game progresses.
If you go warrior there's no reason not to put everything in STR because even if you take magic skills or whatever you'll be shit with them as the game progresses.
etc
So it turns out that the game is only really fun at the first few levels where your character can still be very effective as an interesting multiclass