I'm thinking of tweaking one of the missions (probably A Tale of Two Moonbases) to give each of the units more specific abilities. Inspired by TF2, I'll make one unit a tank (i.e. lots of health), make one unit fast, give unit high accuracy, and one unit extra melee skill. Any thoughts or other suggestions?
Team Fortress 2 is a popular online multiplayer FPS, where you choose your "class", e.g. gunner, sniper, medic etc.. I could just create another mission rather than change an existing one. I think it will add a new dimension where you have to think about and use each unit's advantages and disadvantages. I for one rarely even look at the stats of my units (which is probably why I don't do very well).
I like the idea but definitely as a new mission. Using an existing mission model is fine too. I think an explosives expert unit with extra throwing strength 18 or higher would be good. Also an engineer able to build things like walls/sandbags for units to hide behind. Maybe also to cut through doors and walls.
Depending on the mission I would like a scout unit. Carries no weapons but has high armour, high Action Points and used to find out what's going on in enemy territory or used as a decoy. Maybe he's allowed to carry smoke to aid decoy or self preservation.