Aggressive to what standards? I don't believe its a ruby green, a lot of the vic haps look very similar and can vary in color based on mood. The ruby greens I have and have seen do not have that bar down the middle. What makes you 100% sure?
The brown bar down the middle is very common especially in younger ones. other signs are the coloring pattern shape of the fins, how far back the dorsal starts and the shape of the mouth. If you compare it to a sp35 or a Makobe the bottom lip is more pointed and pronounced.
A full colored adult ruby green looks much different, which is why it's hard to ID, but in my experience with lake Vic's, that is a staple image of a juvi Ruby green.
In my experience with Vic's they are often confused with other fish as well because they all do look very similar, typically coloring is the only discerning factor, which is unreliable, but position of fins, and mouths are other ways, very very subtle differences.
If you could post a picture of it looking straight at the cam (it's lips) that might help. But I think it is in fact a Ruby green.
Check out livefishdirect.com they have pictures of their locally breed Juvi's.
My profile pic here is a Pundamilia Nyererie Makobe island.