It wouldn't have worked to make it more than the 1 year, this Trilogy is "The Hero's journey".
movie 1 - Hero/Chosen One is thrust into a Destiny/Leadership Role before he's ready, because of his potential
Movie 2 - Hero shows his leadership weakness (still too reckless) and completes his transformation to "The Hero" when his Mentor is killed and finally earns his position by the end
If it had been 4 years in between, that's far too long for The Hero, not to have gained the Leadership experience to not be so reckless and reactive.
One Day I hope to be the Man my Cat thinks I am
Where are we going? And why are we in this Handbasket?