greens are mean, like really mean, possibly as mean as jars, it would never work with just the two of them, but if you see positive signs that it might work will they are divided then it might be worth thinking of adding more aros? 4 min to work and cos of the aggression potential your best options would be black, green or jar, jar is the riskiest to com, and deff not worth risking two jars i a com... but if you got a bigger green and a black or green same size as the jar, it may be a possibility.... Mayb??? always the risk!