Doesn't matter the theme or the setting.

A squad-based RTS like Full Spectrum Warrior but with only one combat unit. Cannot have more than four units in a squad.

Squad consists of a

Carpenter - constructs and repairs all structures
Medic/Healer - heals all other units and provides buffs and debuffs
Combatant - obviously attacks and defends other units
Engineer/Scientist - researches and upgrades anything

...and the real kick
Player designed content for their squad/squads (requiring gathering of materials to preserve balance)

Could either have base building or be Voltron-like, the whole squad is inside an attack vehicle. Or neither one.