Well, that's a very unfair comparison. FFV takes place in a much more idealistic, anime-ish fantasy world where the bad guy is an evil tree that you can just punch out of existence and it's over. This version of Ivalice is much more real in that one person cannot hit overthrow a whole government and expect everything to be okay because he has the moral high ground. And yes, even TA has a more simple world, because Marche knows it's fake and gets to know exactly what to do to get home.

Marche did a fantastic job. He did what he could. When he discovers the system he was raised in is broken he walks away, no longer able to look at the injustice. He later realizes that walking away just won't suffice and noticed that beneath the political struggle lies a far greater threat that he takes upon himself to stop and he does that. It costs him his reputation. He is well aware of that and doesn't care, ready to live in hiding as a heretic for what he did rather than expecting to receive any credit.

And you know, while Delita was vengeful and power-hungry, didn't Durai say Ivalice was prosperous under his rule? That's kinda the whole point of this story. If you want to out-stab all the back-stabbed and rule the world according to your vision, you have to bloody your hands. Ramza could never do that because he was too moral for that, while Delita no longer had anything to lose so he lost himself.