Bristlenose does the best with smaller polys. They only get about 5-6" max, there are some plecos that do like slime coat and are more predatory plecos. I have kept rhinos and sailfin plecos with multiple bichirs with zero problems.
I had leopard pleco with my senegals for years and never had an issue with him going after their slime coats. If anything, it was like they were best friends.