If your choice is to remove either the oscar or polleni... I'd keep the Polleni... theyre harder to come by rather than the oscars which are a dime a dozen
I think ur good, but if at some point in the future u find some agression or think it's too crowded for them, u can always exchange the agressive fish at the lfs for smth less agressive or smaller in size
if the convicts breed I would be nervous about having a polleni in there... ime they are not tougher than a similar sized convict... and they are better than convicts imo, lool