You're lining up an awful lot of "ifs" in a row there.
You don't need 11 different religion-specific missionary units, but rather just 1 generic one. Especially since missionaries now appear to be tied to a specific Belief (Holy Order: Allows the purchase of Missionaries to help spread your Religion), in which case only one religion can have missionaries anyway (because Beliefs are unique).This also indicates that we most likely will not have units for spreading religion like we did in Civ 4, because we'd need 11 units to spread all 11 religions, because they'd have to add at least 33 new units not just 27.