Kanan wins.
Cal had a tough time against Trilla, the second sister, by himself.
I don't think he'd have what it takes to defeat the Grand Inquisitor, which Kanan did very early in the series, to my knowledge.
That's relevant because Cal was 100% a near-equal to Taron, and might've come out his superior in a pure duel.
Malicos has a significant edge in the Force, due to his knowledge of Nightsister magic. Kanan probably has a marginal edge as a lightsaber duelist, but I don't see it being enough to save him from Taron's superior Force ability.
Kanan can barely outduel the Grand Inquisitor with a very situational amp, and he's only marginally superior to much lower Inquisitors such as the Fifth Brother, Seventh Sister, and Eighth Brother. Kanan also had a very situational advantage against Maul. After that, we have no indication that his skills with a lightsaber grew after his blinding. In fact, as evidenced by his loss at Rukh's hands, I'd say he grew less skilled with a lightsaber after being blinded.
I'd say Taron Malicos should win this solidly, despite having some difficulty in pure sabers.