give them food so they grow big and strong?
You may want to take a look in object editor for
- "Art - Projectile Launch - X/Y/Z" to modify from where projectiles start flying (if the unit uses projectiles)
- "Art - Scale" - to increase model's size
- "Art - Selection Scale" - to increase size of selection circle
- "Art - Shadow Image Width/Height" - to modify shadow size
- Possibly "Combat - Attack 1/2 - Range" - not sure how large models handle very low ranges, so you may need to increase the range
- "Pathing - Collision Size" - to increase unit's "hitbox" (so that other units do not pass through it)