Oh yes, that is huge. There are regularly scheduled A&A games, not in tourney form. But the tournament brings in a lot of people. I've never played in the tournament, but I have played in the standalone A&A games at Gencon.
I go to another con some years, World Boardgaming Championships. I don't know if the A&A tournament at Gencon is like this, but there are people at WBC that have played these wargames well over 1000 times. I've probably played Russian Campaign, my favorite, 40 times. So I go out and free play and don't enter the championship tournaments. I don't have much self-respect, I want to preserve what little I have.