How much tougher? It can't get much easier in some weights. Picked a random weight - 12u 110. 19 in D1; 5 in D2. 12u 110 is a very common weight. In D2 south 11 of the subs brackets at 12u are round robins - less than 5 guys. Four of the classes have 1 wrestler or less, leaving 6 brackets in the sub. D1 North 12u - 11 are brackets, 9 round robins and just 1 weight (240) does not have a wrestler.