That fragmentation annoyed me too at the beginning, until somenoe tokd me something along the lines.
"It's like different reddit subs with each hsving their own mods and rules"...
So /c/gaming on instance A, and /c/gaming on instance B, would be like /r/gaming and /r/gamingfornoobs.
There are already some communities with the same tooic, but without much interaction, so I was mainly refering to joining existing ones.
However, even if that happens, one can simply go ahead and create a new community with normal mod behavior.