ST shields are absolute crap. They are so vulnerable to just some fancy frequency manipulations that it's impressive no one built a tool to exploit that(oh wait, they did so they could fight the borg... and proceeded to not use it elsewhere because plot).
Err... no they're not. You're completely misunderstanding how Star Trek shields work and what was done involving the Borg.
Star Trek shields cover all spectrum frequencies usually except for ONE, because if they don't allow that one through, they cannot fire weapons without taking shields down. This is a logical extension of the technology and how it works. Basically, if they did not allow that one frequency through, they would block their own weapons fire. No ship uses the same bypass frequency, and there's no way to be able to detect what the bypass frequency is via scans, the one time it was done against a Federation Starship didn't involve manipulating the frequencies, it involved old fashioned spycraft (ST: Generations).
The Borg, on the other hand, use very different shield technology than the Federation does, they tank a few hits and analyze the weapon fired at them so they can then adapt to have perfect defense against those weapons at those specific frequencies and then proceed to absolutely no sell those weapons. This is why people rotation weapon and shield frequencies when fighting the Borg, they are looking to prevent that perfect defense. Rotating weapon and shield frequencies against other opponents in Star Trek doesn't accomplish anything, as those enemies cannot pull off the same stunt the Borg do.
SW shields, on the other hand, do not suffer that weakness and, based on how much damage turbolasers do to other ships, should be able to resist most of what an ST ship throws at it.
Do you have any sources explaining how SW shields work, or are they like most tech in Star Wars and just another form of space magic that's handwaved away and not explained?
Because that's a major problem when comparing the two. Star Trek shields, at least as the Federation uses, are a combination of gravametric and electromagnetic field that blocks incoming energy and mass using those forces. As such, we cannot say that SW shields would actually block everything ST uses, especially the more exotic particle weapons like Phasers, which are a nadion particle beam weapon... how the hell do nadions even interact with SW tech? One can argue, albeit unfairly, that SW shields should just be bypassed by Trek Phasers since they were not made taking nadions into account... On the flip side, turbolasers are just a form of plasma cannon, a very common type of weapon in Star Trek and thus we do know that, at minimum, Trek shields CAN protect them against that... how well will depend entirely on the calcs you use.
Maneuverability? (probably goes to the Sovereign, but maybe not. Fed ships tend turn like pigs...and ISDs)
Star Trek ships are stupidly maneuverable for the mass and size. Fed ships really don't turn like pigs when you actually sit down and look at their size and speed profiles, folks are just used to thinking of "space fighters" when they think of high maneuverability. Consider exactly how Trek ships move when engaged in space battles, they are much more akin to the movement of planes than they are to slow moving ships. Some of the close calls we see Star Destroyers get into in the movies wouldn't even be a concern for Trek ships, as both would still have considerable maneuvering safety. In fact, one thing Trek ships are vey good at is the very close space knife fight range a range that we only see starfighters operating in normally in Star Wars, Trek capital ships commonly fight each other at. Now, granted, this is in part due to the medium. Trek fights were made to look good on 4:3 TV screens, which meant the ships were stupidly close together when you actually consider the vastness of space, but in setting there's actually good reasons for fighting at ultra-close ranges (Cloaking devices), and we do know they can engage at much longer ranges too.
All that said in defense of Trek, I'm not sure a Sovereign class can beat an ISD if we're talking about a straight pound each other into the dirt fight. Even if my assumptions on tech is true (single Turbolasers being generally weaker than a single phaser, Proton Torpedoes being weaker than Quantum and Photon Torpedoes, and Trek Shields being superior to SW Shields but SW shields working against Phasers and Quantum Torpedoes), the fact that the ISD is a pure warship and 4x the size of the Sovereign really pushes the edge to the ISD. Even with its superior sublight maneuverability, the sheer weight of fire from an ISD is threatening to a Sovereign class. The parasite fighters are of questionable threat... the fighter scale turbolasers I do not think could put a real dent in the Trek shields, and Trek phasers have been shown to have pinpoint accuracy AND wide beam settings, which means that a flight of TIEs (which are UNSHIELDED) are just going to be an exercise in fire control for the Sovereign. Their carried Proton Torpedoes could be dangerous for TIE Bombers, but that's assuming they get close enough to actually launch them.
No, in a brute force contest the Sovereign I think loses. The ISD would know it had been in a fight though, and would probably consider the Sovereign class as punching about it's weight class if put up against a ship of similar size from Star Wars.
However, when we add in the rest of the Sovereign's capabilities, especially it's superior sensor technology, I think the Sovereign might actually be able to pull off a Trek Tech victory, especially when paired with some exotic maneuvers that Trek ships can pull off that the ISD cannot. For instance, we know that Trek can use Warp drive tactically, something you cannot do with hyperspace in Star Wars. Yes, Hyperspace drives in Star Wars are faster on a galactic scale, but a Sovereign if playing for blood and with a crew knowing the capabilities of their enemy could play merry hell with an ISD. For instance, sit outside of its effective weapon range, warp in, unload a full barrage, and then warp back out of weapon range all in the span of a few minutes. The ISD has no counter to that kind of trick. The level of precision targeting the Sovereign can do is also not something commonly seen in Star Wars capital ships, and when you combine that precision targeting with the superior sensors that the Sovereign has (let's not joke, if there is ONE thing Trek has over Wars is that their sensors are WAY WAY better) it may mean that the Sovereign, if given enough time, can find every chink in the ISD's armor and work to exploit it from the old fashioned "beam a torpedo inside to hitting critical power junctures, to destroying the primary shield balls on top of the ISD's bridge. That would be how a Sovereign pulls off a win, by a combination of outside context tactics and Tech Teching their way through it.
But in a brute force contest? The ISD takes it 9/10... and that 1 is more likely a loss due to sheer incompetence on the ISD commander's part rather than anything the Sovereign does.
In a situation where the Sovereign is allowed to leverage the adaptability of a Starfleet crew and tech? Probably closer to a 5/10. Those tricks can get your far, but only so far, and may also blow up in your face.
