I do think Saxon nationalism is anachronistic. I just don’t believe non-nobility had any sort of shared identity like that. In the time period in question most people lived and died within 20 miles of where they were born. Most rebellions started in response to anger at a local lord, and had nothing to do with larger national issues (there really weren’t national issues.)
So what you really had were nobles who fought against the new King, but I don’t even know that that is evidence of any Saxon nationalism. In the feudal era the top-level liege lord of a region changed all the time, and was like as not to have the same language and culture as you. One of the key tenets of feudalism is it was very common to fight against someone you had sworn fealty to–regardless of whether or not they had the same cultural background as you. Brothers and fathers went to war against each other all the time, that was just the way it was.
If there was anything akin to Saxon nationalism I think it was just that it gave nobles a “good excuse” to try and topple the King. If you look at history of feudal Europe people were big on advancing claims and justifications for doing their warring, be it based on random invented (or real) ancient claims or deeds, disputed lineages or etc. A Saxon who wanted to try and become King had a powerful tool in that he could go to other Saxon nobles and use the current King’s “nationality” against him to help recruit co-conspirators. But I don’t think it was truly anything like nationalism in the present sense. It was more about personal avarice and desire for power, not an idealistic or emotional connection to some vague sense of “tribe.”
As I understand it, this also gave William the reason to wipe a lot of them out and therefore reward his friends, the one who helped him get to be king, who also happened to speak French - as the new nobles over the land. If you insist on fighting the new king, don’t be surprised if he wins and your family is dead.
In an era of single shot breechloading rifles, they did consume what would have seemed like an awful lot of ammo. Compared to the recoil-operated, belt fed designs that came on the scene in the closing years of the 19th century, they were actually pretty leisurely in their rate of fire and anorexic in their ammo consumption. They couldn’t fire any faster than the operator could turn the crank. That guy’s arm muscles had to make everything mechanical about the gun work. No energy was harvested from the cartridges for any part of the feeding or extracting cycles. The main reasons they never saw much use were:
Weight. They weighed as much as an artillery piece and were mounted on similar carriages. In an era where much of US military activity consisted of chasing Indians, they were rather too clumsy to drag along a great deal of the time. IIRC, Custer had at least one, and elected to leave them behind.
Nobody had any real idea how to make good use of them in battle. The French had the conceptually similar Mitrailleuse and it’s failure as a battlefield weapon illustrates what I am talking about. Since the early “machine guns” looked kind of like artillery, there was tendency to try to use them like artillery. Machine gunnery really got figured out just in time for WWI.
OTOH, the Gatling and its kin did see a fair amount of use by various navies around the world. Apparently, mounted on a boat they must have been pretty useful for hosing down folks who still thought largely in terms of spears.