Units can be assigned / garrisoned inside bunkers or castles.
These units will be activated during base defense.
Each unit, takes the following Storage Capacity per type (unit level does not matter):
|Unit Name||Capacity Taken per Unit|
|Bazooka Batass||6 or 7?|
Example: Bunker level 4 has Storage Capacity of 15, so it can Garrison either 5 Gunners, or 1 Walker.