maybe when a certain number of the same troop are within a given space they get an attack bonus
20 barbarians= +15% attack speed
20 archers= + 5 attack
20 goblins= +8 movement speed
!0 giants= + 100 health each
it can be varied but the idea of mobs being used would be nice
The benefits can also change depending on the troop level and number of them

