As to MHR, you're right, there is virtually no overlap with Triumphant. MHR is based on a dice pool mechanic and most character aspects are rated d8 to d12. Triumphant has a broader range (of dice) and more of a simulationist approach - meaning you play a super-powered character in a wide-open adventure and the result is comic-book style action. MHR took a different of angle of playing a comic-book foremost and the resulting action was inter-related with the characters in various ways.
Savage Worlds is more traditional role-playing that, to my knowledge, doesn't scale well into the superhero genre. Although the core of SW is quick and easy, once exploding rolls, bennies, and soaks start flying around it is not nearly as smooth as I'd hoped. And it has a tactical aspect that can be a challenge to handle for online games.
Triumphant looks like it will be smoother and easier than either of those, but yet robust enough to capture the wide variety of the genre.