Just trying to be more realistic, I like the concern but disagree with the fix.
Honestly, stamina shouldn't really be all that directly linked to submission efficacy. Now on the flip side, I think submissions should be harder to initiate, and stamina SHOULD play a role in the initiation/denial battle.
I hope that makes sense. And just to make this more clear, if Maia or Jacare got anyone in a submission, it's getting finished even if it's in the beginning of a fight. However, in mma, it's not so easy to get it set up and locked in... And the delta in stamina between the two contestants should play a factor in the set up stage (just not the escape stage).
So maybe expand the denial window and place emphasis on how big the denial window is based on stamina. But I think once locked in, you should be toast against guys like that