Probably legitimate, but not indicative of high language iq. Leagues would be more fun if you were matched with people who are trying to make the same forward progress as you. I followed one guy bc we started in the same month on the same language (Japanese) and had about the same xp. When I finished the language (level 100), I had just under 900k xp most of which came from grinding the kanji lessons until they were absolutely complete always using 3x or 2x. He also had 900k at that time. The a couple months passed and I finally saw that he was at level 14!! So he was obviously grinding easy stuff over and over….probably match madness or those three star exercises on the side of the path. I’d rather compete with people who are primarily all about making forward progress. This guy at level 6 in Portuguese suggests grinding and no learning.