Murder in the Malawi Tank

I came down this morning to find a dead Yellow Lab. I instantly thought
it was the tattered beaten up one that I've been trying to catch and
isolate for the past few days....but no...she is still swimming around
and keeping out of trouble. It was a perfectly healthy (until this
morning) Lab. It was pretty badly chewed up.

I have two suspects that are beating on one another so much that they
now both have sores on their mouths...and one of them bit me the other
night. Allegedly, they are Maylandia Lombardoi but from what I can see
I'm now suspecting they are "mutts" - I have 4 of them - 2 are slightly
bluish/white, one is very yellow and the other is a browny yellow. It is
the yellow and the browny yellow that are fighting - they are now 4-5
inch plus and very fat. From the fry in the tank I'm a little confused
about their origin - deep blue with black vertical stripes - doesn't
match anything else I've got so I'm guessing they are from these fish.

Should I oik both of these fish out of the tank and trade them in as
they will certainly kill one another if not other tank companions?
Should I leave the status quo as if I get rid of these two Mbuna's by
their nature will then fight again and another dominant fish will
emerge? Should I pick one and keep it and get rid of the other one?
"Innocent" fish are getting caught up in their war...

Gill