Overtime is a problem.

[Themarvin]

I don't think people have anything against overtime existing as a mechanic, it's just that it should have a time limit of its own. It's very rare but you can get matches that go over 20 minutes because the teams are quite evenly matched and neither team can actually break the checkpoint.

Then may the ones the has the most fatigue lose... it is natural selection by then... and yes 20 minutes is fine.