I would bet that if the Moham-madmen” start shooting that when the dust settles, there will be a lot fewer Moham-madmen in Phoenix. I would also suspect that if they start shooting from the “mosque” that the bikers will rightly not treat it as a “house of worship”. They will treat it as what it is—a fort. I would also bet that a hot round in the right place will cause the “mosque” to self-destruct.
If it hits the explosives they have stored in there.