I at one point had a pair of both clarkii's and gold stripes...this was in a 72 bow front... never really had any problems... the goldstripe female was about 3-4 inches and would try to bully the much smaller pair of clarkii's but with no luck. Never had them breed at that point so they never got as defensive as they could... I deffinatley wouldnt advise mixing the 2 in your nano both for the size and agression of the clarkii.