You do realize that a 75 is a far cry from a 180, right? You can't compare the two or how fish behave in each. I have a 180 and I've moved fish into a 55 and their behavior has completely changed.
I hope it works for you, but you need to keep an eye on these fish, especially as they mature.
Not trying to beat you down, but you need to be aware of the possible situation you've created in your tank...
