Okay, so firstly, counting the number of alternate Moris that were summoned, there are 9 excluding the main universe.
Each alternate universe should be a different space-time continuum, as they describe their experiences in their own worlds.
In episode 555, you have them describing their own "Tathagatas", such as "Your Tathagata is small.", "Ooh, it exists here too, Tathagata's failed weapon, I mean. My world was wiped out because of it.", "So, here Mujin is Tathagata. In my world, he's that one guy everyone picks on.", "Where I'm from, Daewi Han is the Tathagata.", "Mira Yoo is my Tathagata.", "In my world, miss Mira and I tied the knot.", "The 6th letter is the worst. It destroyed my world."
It's also supported by the different powers, conditions and appearances the alternate Moris have.
Hopefully this is good enough?