Hmmm, but it eliminates the possibility of a ground battle, and a Caedus' fleet is at somewhat a disadvantage compared to Vader's given the lack of a powerful capital ship. (While Malgus could have the Ascendant Spear.) But it is a possibility.
We've seen far too much of Malgus on these forums. I'd rather hash out the details of Caedus' forces for a battlefield consideration, since they exist and there's a wealth of information available on the weapons of the time period.
Furthermore, Caedus' forces are differentiated from Vader's in many interesting ways. Compare the composition of their fighter corps, etc. as a starting point. Caedus is basically like Rebel Alliance enhanced.
I think that if the composition of their forces was set to be roughly equal, not accounting for differences in armament and vehicle choice, that you would have two technologically comparable forces led by capable Sith Lords who both have demonstrated a sound grasp of strategy and are accomplished duelists themselves.
Also, they're both new to Kaggath, so it would be a refreshing break from the Traya, Revan, Malgus, Vitiate, Palpatine types who've been hashed out time and time again here.
P.S. Still need a matchup for the Ohnaka Gang, Nightsisters are no longer an option.