I have 1 rite not it is about 7-8 inches and I love it ! It is a male, and he is very aggressive but he has not knock off anyone yet. He is in the tank with 2 midas, 3 cubans, 2 festae and a rtm.
Though I like Grammodes, Ciocca is correct. I have a 4" Costa Rican male in with my Freddies, RTM's, Cubans, and more. I have found that they really get nasty when a pair forms. I'd say if you start with a small one, you would be safe for a good 8 months to a year.
The thing about grammodes, is you may not see it at all until it reaches 5-6". They prefer to hide. I have a pair that has had 2 spawns, and are never seen unless challenging a danger to the spawn.
And they don't like company, if they are not dominant they will hide, if they are dominant, their tank mates will be dead.
Well when I get it it will go with other fish but once it stops tolerating tankmates he will get his own tank. One comment has me thinking I should get a dovii but ithink the grammode will be a better fit for me