Chad wrote:
I agree with Petr, I see no reason to put them on different wikis. Namespaces are cheap.
Namespaces are usually a pain in the ass. Sj's post on the subject: https://meta.wikimedia.org/w/index.php?title=Talk:Wikimedia.org&diff=365735 6&oldid=3657294#Separating_the_wheat_from_the_chaff.
From his post: "... but that would address many of the reasons that people
fragment what are otherwise sensible critical-mass communities or projects into multiple beautiful-but-subcritical communities which fade over time."
MZMcBride