It kinda makes sense. I'm guessing you have to be pretty strong to survive the Vizard process or something.
It makes sense for Shinji anyways. He seems pretty damn strong. And all the other Vizard were managing okay against Ichigo's fully hollow form
Remember, Soul Society makes very little sense. It's rank structure is based purely on how powerful you are in combat, as opposed to something like, say, how could a commander or leader you are. Your knowledge of battle strategy, your ability to tactically plan or your administrative talents.