Heres my 2 cents. It should be up to the kid. Some kids, mine included feel like they have an edge over the other kid when wearing certain singlets. Go to national tournaments high school included & see the swap meet that is going on in regards to singlets. The warm up, hat etc. is plenty in my opinion to achieve the team feeling, sitting together too. But when it comes to the singlet, that is when it is go time & until the team is out on the mat with the competitor he is very much alone with the other kid that wants nothing more then to beat him. I personally do not think it is the coach, parent, or board members place to take anything away from the kid that gives them the edge even if it is only in there mind. Remember what they say, this sport is 90% mental.