Have you perhaps thought of making your Patreon into charging upfront? That's been an effective way of keeping fake patreons away. :D

That is the best thing to do to safeguard yourself from this I think

Unfortunately, that option is not available for everyone, as it's still in beta.

if the patron has only one creator in their list, google search: [patron name] [patron email until the '@']
if you find a twitter account with the same name and same icon, that will be a fraud, it's a fake account

So these four suspicious patrons does followed just me and no other creators on their list. I looked these email names on Twitter and only 3 has same name and icon, only one called "_art55_" doesn't exist on Twitter.
Also these four patrons pledged in same day and same time, and they haven't paid that pledge for 3 months.

block and forget, at least for the three that are on twitter too you ca be sure, for the 4th...block anyway, at least you'll have a more precise expectation of your monthly payout, lower but correct. Also notify to Patreon these account and the scheme that they follow, this problem affect around 10-15% of all the patrons

oh, that fourth one, "art55", had twitter account but it removed, so I blocked all these four frauds.
Where you know these trick?

Also how you get real patrons? Should I change these rewards on better way?
I think I should remove that $25 pledge because some commissioners bought on there.
Or what about some art packs? I made so many pixel-art fonts for just fun or boredom, so I would sell those for someone.

I've just saw a weird pattern in the last few months, no one would use real information when following a fetish creator, even less if, among those patrons, there is a Muslim. I've tested the hypothesis and it turned out that I was right, until proven otherwise. But Patreon doesn't seem aware of this problem

About the patrons, offer a service instead of a product, like high res at 5$, early access high res at 15$, exclusive stuff on demand at 25$ and, always, *always*, ALWAYS, quality over quantity