Why use your own units? Only yellow golems are deployed on the battlefield.
Academics have the highest knowledge stat; do they really have mana problems? If they do, there's nothing stopping you from taking artifacts and skills that boost mana and knowledge. And on random maps, I often have a mana well.
You can search online (and there are even videos) on how to achieve Utopia in 1-2 weeks using the Build, Deploy, Power strategy. And it's easier for mages to do this – they can deal more damage in a shorter time thanks to their powerful spells.