[DaItalianFish]

Well in terms of similarities to the other routes, there is no doubt the end result would have been similar to the Fate route.

Spoiler:

This is kinda obvious seeing as Shirou ends with Rin in UBW, whereas Archer didn't even know that the person who saved him was Rin. And Heaven's Feel is self-explanatory. So Fate is pretty much guaranteed to be the most similar.

At the same time, that doesn't have to mean the actual events of the war were similar to Fate.

Spoiler:

A big key thing to understand is that Nasu has said the chances of Shirou becoming Archer from ANY of the known routes is basically zero. So the real question is: why is that? If we only look at the Fate route, the most likely reason would be Shirou's love for Saber. But there could have been other reasons as well. Like if the speculation that Shinji was the one who betrayed Archer in life is true, that would be another difference from Fate, and might've also played a part in Shirou's transformation into Archer.