Damaging the above mentioned guard with the lowly spell before finishing him off with some club is not unbalancing, since the wizard tends to have more in INT and less in AG, STR and CON.
Yeah, that's fair. While a wizard is less apt at combat, the right spell will halve the opponent's hitpoints giving the wizard the edge it needs. But I suggest that you don't deny yourself Agility, even as a wizard. In
Divine Divinity, I was about level 30 before I spent any points on Constitution because my Agility was high enough to not get hit.