I have 30 Tropheus Kaiser 2 (Kiriza) in my 180 and I know there is room for a total of 40 or 50 fish in there - maybe even 55.
So yes - you have room for 40 fish.
Should you keep two varieties?
I don't know that one.
I am considering adding a second group but cannot decide.
Pros would be nice color contrast and busier tank.
Cons might be interbreeding or one group not breeding much.