If you have more than one Patron Wizard on the field (let’s use 2) and tap a wizard to use its ability does it happen twice because there are two Patron Wizards?
No. Patron Wizard has an activated ability. You must choose to activate it and pay for it to get it to the stack. That payment is only for that one instance of the ability. A second Patron Wizard only gives you another wizard to activate the ability with, and a choice of which of the two (identical) abilities to activate.
Former Rules Advisor
"Everything's better with pirates." - Lodge
(The Gamers: Dorkness Rising)
"Any sufficiently analyzed magic is indistinguishable from science."
(Girl Genius - Fairy Tale Theater Break - Cinderella, end of volume 8)