I do wonder if Zero Hour perhaps showed us a potential weakness for Thrawn (besides being blindsided by something he had absolutely no way of knowing about). When Thrawn has someone he considers a worthy opponent, like Kallus or Hera, he has to make sure they know he’s beaten them. HE’S beaten them.
Thrawn did not have to jam Kallus’ signal. In fact he needed the transmission to go through and cutting it off like that made the rebels more paranoid than if Kallus had gotten off a full warning about “don’t attack Lothal factories” instead of “Thrawn knows about-” and nothing else making them go into hyper-panic mode speculating and instantly react when Thrawn’s fleet is on the move.
So jamming the signal and then Kallus getting it out and then realizing Thrawn’s plan is done entirely for the benefit of messing with Kallus, of letting Kallus know Thrawn has thoroughly outsmarted him. In order to drive it home Kallus is left alive in order to watch the battle–a bad move even when Thrawn was there with him, but when left alone with Pryce? He escapes, which he could only do because Thrawn was more concerned with crushing him than beating him and being done with it.
And why does Thrawn leave Pryce in charge of the fleet? He wants to head the ground assault. A little confusing since you’d think they’d use Imperial Army divisions for that (Thrawn himself is Navy) but his conversation with Hera makes it clear what’s really going on. He wants Hera to know he’s beaten her, just like with Kallus, and again took a risk in doing so–leaving the fleet in command of a bureaucrat who while competent still starts to crack under pressure she’s not used to and Thrawn himself is left totally exposed on the surface. If the Bendu hadn’t shown up it’s entirely likely the Rebels would have rather fought given surrender would only keep command alive anyway (Thrawn made it clear he would kill everyone else) and while they had them surrounded that still put Thrawn in fairly close proximity to a Jedi Knight who could likely take out several of his men and him before going down (to say nothing of everyone else who’d fight before going down). While the Imperials would win the skirmish there was no way for Thrawn to know how it would go overall and his putting himself, the commander of the whole operation, at risk to get some smug face time with Hera, is a bad move.
And the thing is…I think that flaw can be entirely in character. Look at who Thrawn is–the only non-human in high command in the Empire. He’s only there not just because he is brilliant, but because he has proven that brilliance to others time and again. It’s entirely likely that Thrawn is so used to having to prove he’s better to such a higher degree than everyone else that he has to make sure an opponent knows they’ve been beaten and that it was him, Thrawn, who did it. And no one in the Empires going to correct that flaw because they’re so used to Thrawn being an utter genius and proving it that they don’t really realize it’s a flaw, just Thrawn proving he’s better as usual.
Given both Hera and Kallus escaped him this time, it’s likely to develop into more of a fixation and that may bring about Thrawn’s downfall. Possibly by eventually leading to over-fixation on either or both of them causing him to develop a blind spot at a crucial moment. On the other hand, that fixation will also make him more dangerous until he’s either beaten or reassigned elsewhere.
Nothing will bring me down, except dancing. A war without dancing is not a war worth having…