Your mage should check for targets with low magic armour and shoot them, or focus on setting up magical threats or summons or something.
It's hard to near impossible for one magic user to do everything you'd want from magic. They don't have the ap to heal and damage, cleanse and do area control. It'd have to be a lone wolf and it'd still be a stretch.
Conversely, it's fairly easy to have the one physical damage guy, amidst 3 casters, but then expectations for him would be low.
You're missing the point. Classes like "Battle mage" are strictly inferior to "having another 2h warrior" as a by-product of the armor system. The strongest party is 4x 2h poly warrior - maybe with some rangers mixed in. Seems wrong to me.
