From what I just read in the profile for Red Tail Shark it is somewhat of a scavenger itself... see below... so IMO you would have 2 fish with the same purpose. I may be wrong here.
Extant fish in this genus primarily graze on aufwuchs--algae
, small insects, crustaceans, worms, small invertebrates and detritus
. Omnivorous, they should be fed greens along with the standard aquarium flakes, worms, etc. They have inferior mouths (downward facing) so sinking tablets and pellets containing vegetable matter (algae, spirulina) will be appreciated, with feedings of blanched greens, peas (shelled), cucumber, chopped fruit for variance.
Read more: Red Tailed Shark (Epalzeorhynchos bicolor ) Profile
My understanding too is that the Bristlenose Pleco is the best Tank cleaner to have and yes they need wood in the tank. Best worker for their size. So you will not see the benefits if kept in that little holding tank.
As the RTS needs 48 inches in length of tank and he is getting quite big, yes they do get nasty, have you considered re-homing him? I'm assuming this is the only tank you could put the BNP in? I myself would not want to keep that new BNPleco in that little breeder for too long. JMO.