Yes, but not, say, at level 5! And also, when you have an Archmage, and you want to, let's say, upgrade something, but you're not allowed to when making your choice!
What's the point of the +20% bonus to Archmagic if you don't use combat spells?!

Zdob, sorry, but I can't quite picture an Archmage at level 5. Probably because I don't need an Archmage like that myself! An Archmage is a cool character, at least from level 8-10. At level 5, a mage can still be, let's say, a spellcaster, an illusionist, a wizard, etc.
And also... I'm not forbidding the use of combat spells. I just think that when you can combine spells (and preferably from different schools of magic), that's primarily a plus for you, you improve and develop in the game, and you develop tactics. This is better than just blasting with a bolt or lightning.

Archmage is a worthy hero class choice (from what's available). Although the options aren't very good.
I would personally choose not because of the bonuses, but just for the sake of interest. Order+Nature, Order+Chaos.

I play as an Archmage for fun. It's 100 times more interesting to play as one. But the bonus is also a nice addition :) And the options are very good.