Ah, I see.
One of the Sensei's I've had the pleasure to train with was an uchi deshi of Saito during his Iwama period. He definitely did incorporate them earlier than san dan.
But what Chris said below brings light to what Saito might of meant, considering he received sandan in a much shorter time.
Sandan in my style means finished student, it takes a very long time.
They are just titles in the end I guess.