I still wish they had maybe segmented some of the story so that some of it was saved till act 3 at the earliest.
I just started the campaign myself but I already feel that certain RPG elements come a bit too early.
This wouldn't be a problem if the story arcs spanned the whole length of the game but if they're as short as you say then I think they could greatly benefit from a slower, more drawn-out pacing or segmentation as you suggest.
For instance the second pair of generals arrived right after my very first RTS victory which I felt a little undeserved. I wouldn't mind having to show a bit more merit by winning half a dozen or more battles before attracting the attention of additional generals.
Similarly, if ambassadors didn't start arriving until their people were actually present on the strategic map or perhaps if they even waited 'till I capture a province their people inhabit, I'd be fine with that too.
There's no shame in not having an RPG event for each and every turn, but in that case, the content should be portioned and spread evenly throughout the length of an average to long playthrough.