I find it absurd on priors to think that soccer of any demographic could result in more concussions than any of those five full-contact sports, particularly the three where part of the objective is explicitly to hit your opponent in the head very hard if you can. (Even factoring in the fact that you do a bunch of headers in soccer.) (Maybe if you do some trickery like selecting certain subpopulations of the practitioners of these sports, but...)
I find it absurd on priors to think that soccer of any demographic could result in more concussions than any of those five full-contact sports, particularly the three where part of the objective is explicitly to hit your opponent in the head very hard if you can. (Even factoring in the fact that you do a bunch of headers in soccer.) (Maybe if you do some trickery like selecting certain subpopulations of the practitioners of these sports, but...)