I keep up to 2 young common bushy nose plecos in with my breeding pairs of Discus but I replace them with smaller specimens by the time they get about 2 inches. I have never had any problems doing this and the plecos do a great job of keeping the sides and bottom glass panels clean. I siphon out accumulations of detritus but I never have to wipe down the glass.
L200 plecos are fine in a large community Discus tank but they are not algae eaters so you will still need some bushy noses for that duty L200 plecos are more of a carnivorous species aaalthough not likely to bother a discus. I have never had a problem with common bushy noses harassing or attacking Discus sides. I can only guess it must be a bushy nose that is extremely hungry for it to bother Discus