For the Maroons, If we look at current military uniforms, you have some type of utilitys for every day work, and kind of an A B C Dressy er uniform, for the USMC, the C is a Short Sleeved, no tie, B is a long sleeve, with Tie, A is a B with a dress coat over it. So I see the Maroons as atleast a B maybe A uniform. The Admiral would definatly wear one, maybe the captain, but the worker bees like Sulu, Uhura would be in B's or C's. Something one can work in, but not as casual as say a doctors smock or engineering overalls.
I do like the TMP in that they were "Everyday" wear and looked comfortable enough to work in them day in and out. with Kirk wearing a more fancy version. For the Maroons, Kirk in Generations wore the "Vest" type of outwear, I would think that would be on a level of the B uniform with out the jacket.