james-
if your planning on breeding them, then yes, keep them in a smaller tank.
Your main display tank will most likely prohibit you from easily removing the brooding male, or the hiding young once they are released. Additionaly, if you can't capture th efry- which you won't- then you'll have issues bringing food densities to the young.
Now if your planning on an occasion fry or two, then sure leave them in your main tank