Once I had that thought, I was off to the races
Wizards of the Coast has its own written stance on proxies, in which they state: Wizards of the Coast has no desire to police playtest cards made for personal, non-commercial use, even if that usage takes place in a store. What is the Point of a Proxy
So unless there is some pattern where similar cards appear to be rarer or more common, or the sample size is a lot larger, brute force wont deliver definitive answers (though it is still interesting of course)
With a strong matchup against decks like Miraidon ex, Raging Bolt ex [Twilight Masquerade], and even Roaring Moon ex [Paradox Rift] - Charizard ex seems to have it all
You can set preferred printings of your cards either in the deck editor or in your Collections page, which is a button on the lower left when you open up Decks from the top left menu
Its quick and non-destructive, which makes it a good first passespecially on trades