Just so you know, SAE's ARE a social fish and prefer to be in groups. I've kept 2 together on two occassions (well, still have two pairs in two different tanks) and that seems to be enough, but I'm sure with more, their behavior is even more enjoyable
They are completely peaceful. I have two in with Fancy Guppies and they don't even pay attention to the tiniest fry....then again, no one in the tank does
There are also a pair of BN's in the same tank, and they really don't pay any atention to each other. They do eat from the same bottom feeder tablet and no fighting or anything takes place.
The SAE's do prefer to have lots of swimming space. They like to play tag, zooming all over, and are a FAST fish. They are good algea eaters, but will nibble plants. They ate my Java Moss down to stems, and I've seen them nibling on Corkscrew Val
HTH