This is just something new I'm trying out, might continue this on with different types of fighters if I have the time or interest. Anyways, here are my thoughts on the X-Wing's heritage.
According to canon, the heritage of the T-70 X-Wing is as follows:
Z-95 -> ARC-170 -> T-65 X-Wing -> T-70 X-Wing
However, there is an 'Oddball' (heh) in this list, and it is the ARC-170. Visually, it only slightly resembles an X-Wing in the fact that it has S-foils.
While I feel that the ARC-170 could conceivably have come from the Z-95, I feel that the T-65 X-Wing could have (and in my opinion, should have) been a separate model line, also coming directly from the Z-95. Adding to this, according to the Legends universe, the ARC-170 was used during the Rebellion by both sides, and was considered an 'elite' unit.
Due to this, I feel the correct heritage of the T-70 X-Wing most likely should have been represented in the following way:
Z-95 -> T-65 X-Wing -> T-70 X-Wing
l
V
ARC-170 -> whatever would be designed from the 170
Now, had George Lucas filmed the series in order, it would have been possible to see ARC-170s try to make the trench run, or to see them escorting the Emperor's shuttle, or even try to take out the Death Star II's reactor core. Heck, it would have even been possible to see whatever an upgraded version of the 170 would look like in episodes VII-IX.
But, since the movies weren't filmed chronologically, it seems that this fighter of the Clone Wars era is relegated to the scrapyard of hate for all things prequel.
Anyways, just some thoughts about the venerable X-Wing's heritage. I might post something about the E-Wing or the Z-95 next, as they are both fighters that pique my interest.
Edit: Honestly, after thinking about it, I probably should have posted this in the Off-Topic subforum, but oh well.
Edit 2: Also probably should have made it about capital ships, as it would have fit the Armada theme.
Edited by ianediger