Crossfire of normal RX580 and mining RX570?

I'm thinking about doing a CF. Now I have RX580 Nitro+ SE, but I'm looking for a 2nd card. Was thinking about 2nd Nitro+ SE or Nitro+, but they cost a little (have enough, but if I can spend more...) - 500 (Nitro) or 550 (SE) PLN for the cheapest ones (used ofc) - it is 120/135$.

Than I thought about RX480 with RX580 BIOS, but there I would need one with 100% working BIOS and Strix OC would be best coz of (I believe from what I read) best cooling capabilities of all RX480 cards. Found one, but seller already bricked two cards and is not willing to play with more.... (there I would pay ~400 PLN = ~100$).

Than I found, here on reddit, info that RX480/580 + RX470/570 would be practically same as two RX480/580. That gave me more field to look for cards. And I found "holy grail" - Nitro 8GB for 280 PLN (70$). Only problem it is mining one. Do You know id it will work with normal RX580? Present one would act as video out card, so I don't mind that it doesn't have any ports out. But... WILL IT WORK? AS Mining RX570 has clocks at 1420/2250 and Sapphire RX580 has 1430/2000, than there won't be a lot of difference (and RX570 will be 2nd card not the main one).

PS. Right now I would like to thank for all the "CF is dead", "sell it and buy newer GPU", etc. comments. I don't have time, money to do that, or don't mind, or give a f. Thanks, danke, merci, dziękować!

Even if it worked there's precious few games that can take advantage of dual GPUs and you might even end up with less overall performance with twice power usage.