The stamina values that are currently on live I think are good, although I have 1 suggestion.
Make it so that if you continue to swing your weapon while at 0 stamina, it will stop stamina regen for 1-2 seconds. Right now what I've noticed is that at 0 stamina you can keep spam clicking on your enemy and just wait for stamina to regen and still get a good amount of hits off. I think it'd be good encouragement to step away for a sec and stop attacking if your stamina reserves run dry.
Just an idea.