I don't think it's effective to try to buy Patreon supporters. Unlike Twitter or YouTube, where you are buying a few clicks (which can be automated, if needed), a Patron is sending you money. I doubt Patreon wants to let people goose the numbers any more than Twitter or YT. And I think it's easier for them to prevent it.
It would be funny if they checked his donor list, and it was filled with $1 donors whose email addresses were all "lloyedevans" and a sequential number. But if it was possible to buy Patrons, I bet he would have done so instead of watching the number drop so much, so fast. At least some of his Patrons must have discovered Evans's personal issues when they wondered why his supporters were leaving in droves.