That's just B&E for you. They made frames for S&M, Homeless, Brackens, Revcore, Badd and Company, and Hyper. They couldn't even keep the parts bins straight, let alone stick to a serial nomenclature convention.
I had a 1992 Badd and Co. that left the factory with S&M Dirt Bike decals. The drop said BCP2***. It had a 21.5" TT. So even if it had the right decals, it would have been the wrong serial. It had a Pro serial, when it should have had a Pro Long (BPL****) serial. The funny thing was, it did have a serial number that might seem right for 1992.

As I said, I think it was coincidence if they matched up to year properly. Perhaps, they had intentions to have serials make sense. They just rarely do.