Surprised this one doesn't have more takers.
I'd argue Malgus loses in a sabers only match, as Qel Droma has an arguable speed advantage and comparable strength to Zallow.
Droma generated numerous after images while training before going to Iziz, outran Mandalore's blaster bolts, and attacked multiple beast riders at rapid intervals.
Malgus's best speed feat is arguably moving his lightsaber fast enough to form a shield, and keeping up with Leneer's speed. Droma is slightly faster imo, has comparable dueling feats (though being able to hold his own against Kun is worth more than Malgus's feats), I think he could narrow a very slim majority.
I don't know...