Here's my 2 cents:
Yes, depending on the size at the time you get them, and the maximum size they reach. I don't really think it matters if they're fish eaters or crustacean crunchers...
I've got a tesselata and green in the same tank...I did have a blackedge in there...it was MUCH smaller than the other two...and became lunch (sort of) for my green (before he regurgitated him.) It sucked. The tessleata and the green face off from time to time, but they've been in there quite a while, and no problems. Before I got the green, I had a snowflake and tesselata (and the blackedge together), and all was well with no problems.