Enemy Territory medic becasue he can cast Revive and Create Medikit.
Enemy Territory field op because he can cast Airstrike, Mortar Bombardment and Create Ammo Pack.
Asheron's Call mage with a Drudge Scrying Orb, Foci, a pack of charged major Mana Stones and full spell lists. I reckon between Mana Boost Other, Infuse Mana Other, Revitalise Other, Revitalise Self, Heal Other, Heal Self, Stamina-to-Mana Self, Slithering Flames, Bed of Blades, full banes and some portal spells we'd be set. The field op can provide the spell components. They're ammo, right?
Find me a decent rifle and get me a good view of a full car park and I'll smash windows in the distance until an alarm goes off ... then the field op can call artillery on in while the zombies are all closing in and we're safely 400m away.
If they weren't static, one of the priestesses of Akatosh would be quite handy. Cure Disease. Cure Disease. Cure Disease.