i have kept an acara with a mated pair of kribs and a pair of firemouths, 2 angels and a dozen neons.
my decription of the acara is that it was a lazy aggressive.
if it could eat or bully something without effort it would - bye bye neons "they just swan into my mouth, honest guv"
but when faced with something that meant he had to put in some effort he just ignored it - the kribs beat it up when brooding.
the firemouth would show all their fire and chase him about
the angels were fine with everyone...
so make of that what you will
i've said before and will say it again
there are as many valid opinions and experiences with fish are there are sources of opinions and experiences....
mine is that the acara is quite a cool fish, will eat anything small and probably ignore anything else