Perfect Susanoo should just be a Indra incarnate exclusive ability.

The incomplete, half body Susanoo should be as far as Susanoo goes for anyone having MS or EMS, but not being a Indra incarnation.

It still is very powerful but not too OP like PS.

It also doesn't contradict anything shown in the manga.

We have seen 3 PS, Madara and Sasuke, both are Indra incarnation And Kakashi who had six paths chakra at the time.