I too have grown a lot of fem seeds and regs and I still haven't had any herm on me, one plant( reg) threw a couple of nanners- plucked em off = unseeded.
I manually ( i got timers) turn lights on/off EVERY night/day, sometimes I'm out of sync but I haven't had any issues with hermies.. I managed to reverse a 3 bears og auto recently by constantly transplanting it and I put it in cold damp closet under cob, and i now have a small amount of pollen ( will select pollenate a couple other auto's that are flowering) i hope the pollen is viable, though.
Anyway I reckon it's something to do with environment that OP has hermies from 3/5 strains, just saying. Happy growing ..