I imagine Palpatine being more inclined with the larger picture politically and militarily, but the Royal Guard would protect those things that he held under his notice. Keeping that occasional threat from an assassin or other dangers would be their responsibility. Palpatine didn't know that Luke was on Endor, but Vader did because of the sliver of Light still in the dark lord. I see Palpatine as arrogant in his power, though perhaps his councilors suggested the Royal Guard, just in case, but also it was their way of keeping an eye on him since typically the "hired help" go largely unnoticed. (Almost like the little birds that are all over the place in Game of Thrones for Little Finger) I know the Royal Guard were sometimes rotated back into normal Stormtrooper service not only to keep up their skills, but also maybe to keep an eye on the Army as well. Palpatine kept all of his leaders in key positions suspicious of one another, that competitiveness also being what made them more lethal when dangers arose. I would imagine the Royal Guard having a military hierarchy and they could answer either to a Moff, councilor, or Intel?
If the Royal Guards were to be "outsourced", I think that the Imperial Security Bureau (which is part of COMPNOR) would make more sense than Imperial Intelligence. Their job is to promote loyalty, root out traitors, and protect/preserve the Empire, which is much more in keeping with the Royal Guards; whereas Imperial Intelligence is more about secrecy and espionage. We do have a Minister of the Interior too, who is the boss of COMPNOR. That said, I'm not sure outsourcing the Guards is the best idea. The main characteristic of the Royal Guards is that they're unwaveringly loyal to the Emperor/Empress. Whoever is in charge of the Royal Guards, Miranda needs to be 100% sure that she can trust them - and that's not necessarily the case with a politician or with Intel, since they all have their own secrets and hidden agendas. It also leaves the Empress pretty vulnerable: imagine if Director Esalis decided to help out with a coup, Miranda has absolutely no one to protect her. If we're going with a Game of Thrones comparison, the Royal Guards are like the Kingsguard... and Miranda needs to be certain that they're taking orders from someone she can trust entirely (ie. not Jaime Lannister). It's possible that the Minister of the Interior might be someone that Miranda entirely trusts... but if she doesn't, then the Guards probably need to be led by someone more reliable.
If I remember correctly the members of the Kingsguard report to the Lord commander of the Kingsguard (senior member of the Kingsguard), who has his/her own seat on the small council, which reports directly to the King. That would keep them separate from the other departments and maintain their effectiveness as the Empress's private instrument. If we follow that same comparison and Miranda doesn't want to be bothered with 'smaller things', the Kingsguard reported to the Hand of the King who made small council decisions in the Kings absence. I think the Executor would be the closest Star wars comparison to having a 'Hand of the King'. The Executor could then relay any information to the Empress that warranted her attention. You could also make similar comparisons to Lord commander of the Imperial knights instead of the Executor. While not being the overall commander of Imperial forces, the position is pretty similar and has that unique quality of answering strictly to the Empress. Keeping in mind the commander of the Imperial guard would report but still not answer to, or take commands from the Executor or the Commander of the Imperial Knights. That would maintain their independence from the rest of the Imperial hierarchy.
Surely the Hand of the King (metaphorically speaking) would be Chancellor Anar? Bear in mind that the Empire has an entire civilian government that exists to be bothered with smaller things. If anyone is going to make decisions in Miranda's absence, it makes much more sense that it be the Chancellor (part of the government) than the Executor (commander-in-chief of the military). Also, don't forget that Joffrey and Tommen were both children who weren't old enough to run the kingdom themselves; and Robert was incredibly lazy. Miranda Tarkin is neither of those things, so she probably wouldn't need her Hand of the King to be anywhere near as active and all-encompassing as Tywin Lannister. As far as having the Royal Guards reporting to the Executor and/or Knight-General... the Guards exist exclusively to protect and serve the Empress, so I'm not sure what there would be to "report" to the military or the Knights? I could certainly see them "coordinating" with each other, to make sure that military/Knight activity isn't going to compromise the safety of the Empress, to contribute to protecting her if need be, etc... but I don't think the Executor needs to be there as some sort of middle-man between the Guards and the Empress. And like I mentioned before, if the Royal Guards are going to report into anyone, the ISB/COMPNOR is probably a better spiritual fit than the Knights or military: they're equally devout/loyal, their mandate is protective/security rather than enforcement/offensive, etc. Kinda like saying that the Secret Service is more similar to the FBI than it is to the Army.
I like the ISB option. I've already written a brief blurb about the ISB and the Knights kind of being professionally adversarial, so it would make sense if we are framing the royal guard to be on that side of the aisle.
To be honest I had forgotten about Anar's position. He would certainly fit the 'Hand of the King' role. Most 'Hands' were Lords, who dealt in military and governing rulings. Tear and Anar would be opposites of that same coin, one manages the military and the other the government. That military perspective of the Imperial Guard is likely why I didn't consider Anar and instead thought of the Executor or the Commander of the Imperial Knights. We all know Miranda is no Robert Baratheon. I was responding theoretically to Akilah's original statement mentioning "Palpatine being more inclined with the larger picture politically and militarily", and if the Miranda was behaving the same way, who would the Imperial Guard report to? I frankly don't think the Imperial Guard should report to anyone besides Miranda. From what's already been discussed it seems their purpose is to serve Miranda and her interests, not the Empire's specifically. Having them report to ISB/COMPNOR would take away from that, in my opinion. But I don't have an Imperial Guard character. I also haven't written anything touching on the ISB and the Knights being adversarial So It's entirely what you lot think is best.
I really appreciated the discussion you all have regarding the Knights vs the Guards. Good reading and perspectives. I feel that the Guards report directly to Miranda. That way, she has complete control over them and that they are loyal to her. I can see a hierarchy among the guards but it boils down to they are protecting and enforcing her will. Having another middle person between them and Miranda would take away that.
