1) Only the outside 2 shoot
2) None of them shoot
I have lost many matches to this

PS: Sometimes it is working then after about 10 mins it stops and sometimes it stops working as soon as I place it.
PPS: It is not due to range because if I put a unit right in front of them they still don't shoot.
PPPS: Sometimes when I break one of them it works but when I place it again it stops working.