Why do ARC-170 Starfighters look like X-Wings?

Question

Something that was very prevalent in the prequel trilogy was foreshadowing. Many things show a sort of evolution into the original trilogy. One that makes perfect sense is the portrayal of the Old Republic. Given that we see the Republic becomes the Galactic Empire in Revenge of the Sith, it makes sense that the Republic has many similarities to the Empire:

To name a few:

• Clone Troopers look like Stormtroopers
• Jedi Starfighters look like Star Destroyers
• Jedi Interceptors and V-Wings look like Tie Fighters
• Both the Republic and the Empire used walkers and Star Destroyers

It's obvious that the Republic becomes the Empire. There is, however, one ship that not only breaks this pattern, it goes in the complete opposite direction - the ARC-170 Starfighter. Instead of resembling something the Empire would eventually use, this Republic fighter closely resembles something the Rebellion would eventually use - the X-Wing Starfighter.

Both starfighters have:

• a long and thin nose/fuseloge
• large cylindrical engines placed between the fuseloge and the wings thin horizontal wings
• long blaster cannons at the ends
• s-foils that open to form a sort of x-shape
• both have the red and grey/white color scheme

I mean, it is as if the filmmakers were trying to imply that the ARC-170 starfighter is some sort of predecessor of the rebel x-wing fighter, which seems to go against the Republic's trend of having things that evolve into Imperial things.

TL;DR: Why was the ARC-170 starfighter made to resemble the x-wing? Have the filmmakers commented on the decision? Is there some sort of backstory/retcon to explain why a rebel fighter would look like a descendent of the Republic/Imperial fighter?

Answer 1

They may have been made by the same company

It’s not particularly surprising that the fighters look similar, considering that they were produced by the same company, Incom Corporation. Apparently, Subpro also produced some of the same ships, so we can’t really be sure that the design of the Arc 170 starfighters influenced the X-wings. It seems likely, though.

The ARC-170s were not in accordance with Imperial doctrine

More to the point, though, the abandonment of the ARC-170 represented a fundamental change in the fighting philosophy of the Empire, as compared to the Republic. The Republic relied on a small number of highly skilled pilots and soldiers (Jedi and clones). As such, a highly capable fighter such as the ARC-170 or X-wing made sense. By contrast, the Empire relied on a combination of highly expensive capital ships and incredible numbers of disposable TIE-fighters (and their equally disposable pilots):

The old Delta-7 Aethersprite was roomy by comparison, the ARC-170 luxurious. Things could have been worse, however. The Goliath could have been carrying a squadron of the new—and seemingly disposable—TIE fighters.

_Tarkin

From the Empire’s point of view, there was no point in keeping the ARC-170s, with their expensive hyperdrive systems and deflector shields. Why bother, when you can just throw pilot after pilot at the Rebels in ships that cost the absolute minimum? By contrast, the Rebellion, with its relatively few, relatively skilled, relatively free-thinking pilots, would want to save every soldier they had, and so the design philosophy of Incom and the ARC-170s would seem very attractive. Thus the X-wings.

Answer 2

They were both made/designed by Incom. When the Empire took control they gave most of their shipbuilding contracts to Kuat Systems Engineering (a subsidiary of Kuat Drive Yards) and Sienar Fleet Systems. The X-Wing was designed to be the main starfighter for the Empire, but Sienar's TIE was chosen instead. The designs were eventually taken by rebel engineers and upgraded for Rebel use.

You also didn't mention the Y-Wing, which was used by the Republic, decommissioned by the Empire, then adopted by the rebellion.

The bulk of this is from the Rogue One Ultimate Visual Guide supplemented by Ultimate Star Wars.