Obi-Wan's presence may have been the primary factor in Anakin's "loss of clarity" as ROTS Vader, and it was Kenobi's familiarity with Anakin's style and Soresu that allowed him to hold him off, his Soresu and Sokan that led to his retreat across an uneven and perilous terrain that eventually led him to the hillside which he happened to notice first and take advantage of with his skill in Sokan. As mighty a combatant as Maul is, none of those edges can be attributed to him, so I fail to see how Kenobi's victory over ROTS Vader implies that Maul would do the same.