You are right about the Defender being an amazing fighter and a hard counter to the Rebel fighters, but that kind of proves my point since there were obviously better options floating around that they could have used, like what the Rebels were using, and they wouldn't have cost nearly as much to get any use beyond swarm tactics out of.
Honestly, this is true, but what the rebels were using very much did not fit Imperial fighter doctrine. Meaning they weren't trained in the proper tactics and use of such fighters, their order of battle was not built to support such fighters, and their supply/ordnance network was not set up to maintain such fighters. Sure, those are all very fixable issues, but it would be expensive to switch over to, say, using the T-65 X-Wing as the main Imperial snubfighter. They could have done it. After all, they had the designs, the resources, and the Incom Corporation had already been nationalized. But it wasn't a good fit for what they wanted to do with fighters. Granted, the TIE wasn't really a good fit either, because it wasn't survivable enough, but it worked pretty well in every other way.
What they really needed was to develop a TIE model that kept it's performance, but mounted shields and at least a couple of concussion missiles. That alone would have vastly improved the survival rates of Imperial pilots, who represented a staggering investment of time and resources by the Imperial Academy system, only to be blown out of the sky by random farmboys from the Outer Rim with depressing regularity.
One of the elements of the Imperial Navy that I find interesting, is that there are hints that many of their ships could actually carry vastly more fighters than they usually do, but they instead stick to a smaller standard operating capacity that is far below their
actual carrying capacity. Like the
Executor-class, for example. Officially, its standard fighter loadout is 144 TIEs. But according to at least one Legends source, the things could actually carry over a thousand TIEs if the Empire chose to max out its hangar usage. And I'm pretty sure that if you removed an ISD's ground assault complement (i.e. all those walkers, tanks, dropships and troop shuttles) and replaced it all with additional TIEs, you could probably double the ISD's fighter/bomber complement. More, if you also used fighters like the Preybird-class (that the Imperial Remnant would eventually use), which cannot use the TIE rack system, but could be parked on the now-open deck space instead.
My pet theory is that the
real reason the Empire doesn't maximize its hangar usage is because they are actually chronically short of TIE pilots. Each TIE pilot is chosen from among the best of the recruits the Navy gets, takes 3-4 years to train, costs the Empire hundreds of thousands - possibly into the low millions - of credits
each, and after all that, half of them get vaped in their first serious engagement. They spend enormous amounts of money on training the pilots, then massively cheap out on the fighters, which ends up wasting all the resources that went into those pilots. And because they are always short on pilots, they can't ever truly use their swarm-doctrine to the fullest, meaning the TIE's weaknesses are dragging down the entire Navy's effectiveness across the board. But no one can do anything about it because Sienar Fleet Systems has an absolute stranglehold on key elements of the Naval bureaucracy, which keeps their contracts secure and ensures that the Empire's hunger for replacement fighters and bombers will never be truly sated.
