“Was Dissolving The Imperial Senate a Mistake??”
Yes - both in terms of morally, (well I suppose empire were well past that already) and practically how it turned out. But for a more detailed look on their intent and it’s execution:
It went all or nothing for the Tarkin doctrine, even the centralized militant moffs doubt an empire without a senate, which was an all but guarantee of a mistake - but even if it failed, as long as the “heads” of the empire: Palpatine, Vader, Tarkin were there to personally hold the moffs in line, the contuity of the empire was guaranteed. But they were killed, and it was not. So yes.
It feels like a cop out, but only could’ve worked if the empire succeeded. It would’ve made their victory an iron grip, but it made their defeat shatter them like glass
As we hear in Star Wars Squadron, a lovely underlooked game, one of your fellow pilots who had senator parents believes that had the senate stayed around it would’ve been a legitimate government structure that could’ve been looked to instead of being over focused on the individual - which led to the moffs being able to break off into warlords
Granted, she’s biased , but it tracks - Palpatine, Tarkin and Vader purposefully made the empire super centralized under them and fostered ambition and infighting between moffs - assured that there’d be no threat as long as they kept them on line, but gave no thought to an empire without them, where the moffs immediately break apart into warlords.
An imperial senate wouldn’t be the cure all - there’s still be moffs who’d break off, and member worlds that’d leave as the war went on (after all, Alderaan was in the senate at one point), but it could keep the lower level essential functions of the galactic government going while the military focuses on the war and if they appointed a legitimate successor then it’d make it much easier for the empire to rally around a strong dictator as they did before.
For a Sloanne figure, having a senate where let’s say half the moffs sign on with her just be being named official Empress, would not only make her a much more dangerous threat - but keep the empire going for many more years if they can name successors and run some kind of government.
Within the OT, it would’ve had some changes too - post Tarkin death as Grand Moff of Outer Rim, things became even more unruly out there, whuch could’ve been marginally more stable with some better government structure there. And there’d likely be more pushback against a second Death Star. Though there’d likely be a mass exodus post Alderaan due to the threat To the senate / their worlds.
not for nothing, the empire dissolved the senate when the Death Star was ready - both because they didn’t need them anymore, and also because the senate would’ve challenged such unilateral authority.
It’s tricky - because it would’ve been better for the empire if the senate existed post ROTJ, but it’d make it easier for the new reublic to absorb at some point, because all the moffs broken apart made it easier to some extent but made it more difficult To root them all out.
And for Palaptine Vader Tarkin, they have no interest in an empire past their deaths - and had they succeeded their grip would’ve been iron, but their failure shattered the empire like glass. The Tarkin Doctrine only works if no one stands up.
Ultimately, the imperial senate was always going to be incompatible with an empire run by those three : they only maintained it to prevent backlash until the Death Star was ready, where they no longer had to worry about backlash. Or so they thought. And as we see, most of all Palaptine, he thinks an empire outlasting its emperor is a betrayal and punished them accordingly via Operation Cinder, burning away anyone but zealots
The imperial senate could’ve maintained the empire post Endor far better than in the original timeline, but that is an incredibly low bar and everyone of any moral worth would’ve jumped ship by then. Would’ve kept the empire as a larger faction going for another 5-10 years, perhaps.