Repost from Beast's Lair, because I wondered whether or not I could get an honest to goodness good response on this, particularly since I didn't get anything polite yet.
Hmm... before you guys start overreacting to me posting this idea here, allow me to say something about it.
I tend to get heavily inspired by others works, even amongst the fanfic community.
Hell, my current project is based on someone else's work altogether, which is a Gundam triple crossover (the other person's story and my idea). The idea came to me that I could try my hand at it, but with some key differences, one of which involves an idea the other author and I bounced around for his story. He wanted to put in either Domon Kasshu, Heero Yuy, Amuro Ray or Banagher Links into his story, so I suggested that he stick with the two Newtypes, and he decided to start off with Amuro later on down the road compared to the current chapter (he posted a SOPA warning as chapter 4 for the time being). My idea's main difference is that I decided to set the story with Banagher as one of the main protagonists right off the bat. The story bases itself where it spans the plots of three different Gundam franchises (Cosmic Era, 00, and some of the Universal Century) and has both an action and a reaction to the whole course of events coming the way it does.
Anyway, I digress. I guess I should be discussing more Nasu-based ideas, instead.
Now, my idea is simply like this, as it's just a premise right now. What if Shirou summoned Amuro Ray as Servant Saver (even though Tomino made it clear that Newtypes aren't meant to be anything super special) because the actions of he and the combined Londo Bell/Second Neo Zeon forces put him in the Throne of Heroes despite the fact that the Age of Heroes is long over by that point?
I don't expect Cherry to know anything on this, but maybe Lantz might know, particularly?