2 separate stamina bars. Once stamina is at maximum capacity any extra stamina gets stored in another bar
Any regular stamina can be converted (for free or for cash) to spare stamina
Why? Because a large base of players spare up stamina for the new upcoming heroes. When sparing you are not able to recharge stamina. This way you don’t waste any stamina. Or it makes sparing easier.
Any feedback on this idea is welcome