This is my take, not any thing I’ve read just so you know.
I think they are different, just as we are all different, given different qualities in order to fit their duties. Just as some of us are given talents that others may not possess in order for the world to work.
I think St. Michael the Archangel was created with a little more assertiveness or a “leader” trait where he is more able to lead.
I think my guardian angel was probably given a lot of good traits in order to help me because he for sure has been working overtime lately haha. I get this feeling God made everyone’s guardian angel corresponding to the traits we are lacking so that they can help us better with our weak spots. It makes a complementary match.