No they don't...
You aren't understanding what Kisu is trying to say.
A 45 rare purple weapon/shield should be stronger than a green/white counterpart, both 5 levels below/higher ones.
50 blues are in their own league and shouldn't be compared to these.
50/56 perms don't have a huge aresenal, from personal experience as both level perms. A 50/56 perm has the option of using a 50 Green/White, Chief Guard, and the rare 50 blue weapons.