I looked into your question and found this. It seems that you "can" mismatch but it's recommended that you don't. Most of your smart mc's will do their best to make up for the lack of balance I guess, but if they're the same firmware but different amperage, I think it would be possible to fly it normally but I wouldn't trust it any further than I could throw it.Can i use a 20amp esc when my other 3 are 30 amp ones but the same brand and everything?