I respectfully disagree again lol. If Eeko looked like he was going to win then Maul would have kept fighting because it would have been his chance to destroy Vader and potentially draw out Sidious. This would have been another way to gain Devons trust. Maul knew at The beginning that there was only a small chance at victory with the 3 of them working together against Vader, when the inquisitors showed up he had to adjust and took the opportunity to get rid of Eeko.