It's possible that the lender may do a little better if they list them each individually but foreclosure seems like a bad path for them.

We have narrowed it down to a duplex in very bad shape, but have a contractor bid to rehab and add a studio in the attic.We have used the BRRRR and have great pos cash flow, even in initial rental.

A landlord has the right to deny any applicant simply due to having a bad feeling about them.

That's a bad sign. 

I think I mostly just got lousy tenants/bad management. 

All that assuming you can get a loan from a bank (maybe someone with bad credit).

What is the best way to solve the issue of bad tenants occupying a house I'm putting into contract? 

As a contractor, if you're shopping for the lowest price you will have a bad time.

If you were a local friend I'd take you out for a beer and then tell you how badly you f'd up. 

If you buy in the bad part of town, you will have issues attracting quality tenants.