Controversial...mildly...cos my aquarium hooligans "on paper" should not really share the same space but weirdly they do.
There are hard and fast "rules" about certain fish...most of which I see as common sense but a newby to fishkeeping might not question.
My main aquarium - 53 gallons - has Rams, an Apisto, Pepper Cories, Bronze Cories, assorted Danios, Cardinals, Neons, Otto's, (inundated) baby BN's, Harlequins, Pristillas, a Honey Gourami, a Flame Tetra and a Platy who has an identity crisis and is BFF to one of the Rams who literally protects it against everything and everyone.
They have been a mixed family for over 24 months now...many of them came from neighbours who passed away during the height of the pandemic, at the time I had 5 x 60 litre aquariums, all mixed fish types and they all moved into the big aquarium together and despite expecting fish WW3, its been amazing.....perfectly well behaved, they all have somewhere to go chill out away from everyone else if wanted.
As I said, "on paper" these fish should not be together...but for me...and most importantly for them...it works.