I have actually seen other teams line up like this. I don't fully understand it.
My only possible explanation is that you are using the same 3-4 personal but really ending up with a 5 or 6 front when the LBs crash the LOS after the snap.
It's my only explanation. But, like I've said, it's used by other teams also.
I don't think the idea is necessarily bad. Just not on 3rd & 1.