Watch out! You've been busted by the posting police. Next time you go over your limit he'll take a finger.
To answer your question...In a tank that size, I don't think you'd have any problem mixing dwarf angels of different species.
I've tried mixing Centropyges in my 120 gallon. Lost a C.hotumatua because of it. Different species (C.multicolor was the offender). Different size. Mortality still resulted. Not recommended.
I was tempted to try 2 in my 180 and after thinking and seeing first hand the fighting I decided no. My potters angel has been a perfect reef mate although my lfs came across centropyge colini. I have never seen one of these amazing and absolutely beautiful fish. After doing my research no way am I going to tempt in tank fighting with these fish. Dwarf angels will fight as my centropyge argi and heraldi did to the argi's death in my 120. I have to say don't try it.
If you're lucky and you've got enough structure for them to avoid each other for most of the time, you can do it. I've kept them together in the past and the delicate balance was maintained until somebody got sucked into the overflow. I had 4 or 5 together for about 2 years before I had any problems because of one's death. It can be done, but be careful doing it.