maybe it works for you but:
one cov ops who knows what he is doing (spot mines/throw grenade/satchell on them) and you will be dead when you come back to replant the mines, your pants stolen and soon the back door open.
(i know, i expect too much thinking about cov ops who actually spots mines)
but engy with medic or just bunch of allies can brute force get through your mine field and get you.
it is all “safe” technique to plant mines there but only if you have bunch of axis on the inside of the bunker ready to kill the cov ops who stole your pants
since the Big door next to it is dynamitable
Finally some defence at the back! 
