If rets would be allowed to use crusader, they can use time in their favor. They are a very good turtle class, especially if playing with a healer. They can just wait for opportune moments, force trinkets, turtle some more, get kill on next setup 100%. Rets are very scary with crusader. This is my opinion.
So, no, I do not believe that rets should be able to use crusader in the tourney. And if they were to be allowed to use it, then at least ban weapon swapping so they can't get double saders and resets.