i supose here a idea for a clan building: barn
This farm should be used to make pets in part whis the "ennemy unit" you want as pet, always % to create the follower is 100% and it cost lot materail, exemple snow dragon, to it you'll want 15 ice shield (if it still be his drop) and then level requiered to craft is the unit level
also it should spawn monsters at his level (exemple lv100 barn will spawn red cyclop or other lower lv) by activate a new action:
to select on a window pets what are here to protect city when no one is here!
(pet get special stats changed by level of barn), each time barn 2* pet original level then all stats are multiplicate by 10
and for finish result of defense level 1:
(thatks to Killer Bunny for have participate to it (LoL)