carthage
PLEASE PROTECT ME STONES
No, Dooku has shown weakness to Talzin's sorcery--sorcery from a powerful witch whom even Sidious was hesitant on facing while on her own planet, so it's safe to say that Talzin is just proven to be more powerful than Dooku. Not to mention that all of her attacks on Dooku required prep, none of which would help in a random encounter. You're comparing apples to oranges, but no not even Talzin has proven capable of outright stomping Dooku with just magic.
Except Kun doesn't need "prep" to unleash his blasts, he was capable of blasting Aleema Keto with one shot. Aleema also didn't prep to reduce her servant to a charred corpse, and the only things that require "prep" in sorcery are rituals to begin with. Dooku's lightning could barely leave Kenobi and Anakin writhing on the ground, and in concentrated bursts its only killed Ventress and random nightbrothers compared to what Aleema did here:
Spoiler:
Not realy her showings to Dooku in SOD take place when she's weakened by draining and possessing him. A weakened Talzin can hold her own against an equally amped Darth Sidious, and stomp him with drain and other force abilities while in a weakened state. Off nexus she still has a wealth of force abilities that outstrip him as well as accolades that place her far above him as a force user
Dooku is likely a lot more knowledgeable than Windu on matters such as sorcery, but yet not even she was capable of stomping Windu through such mean. She wasn't prepared, and had to resort to dueling Windu. Also, Dooku has shown barrier and deflection when he easily batted away his own redirected lightning, which caused a good size explosion. No, it's not the best showing with it, but the ease in which it was done would suggest he is far from weak with barrier/defenses. There's a reason only a few have proven capable of getting passed his force aura. Kun's blasts haven't shown to be as potent off a nexus.
She never utilized sorcery other than blasts against Windu, and had she utilized sorcery Windu would've been toast as well. You've answered your own question because their fight was primarily a duel. A being who can canonically hold their own against Sidious is miles ahead of Windu as a force user. And when has Dooku deflected blasts that can reduce people to charred corpses or disintegrate a Sith spirit? Dooku's shown no talent for absorption and would be hard pressed to fend off Exar's superior physical strength (He was being taxed by Anakin), and a combination of sorcery and Kun's offense would weaken him rapidly.
I'm discounting the notion that there's a large gap between Kun and Dooku in force power (if that's what you're implying) just because Kun is canonically superior to individuals who have shown to be extra powerful in areas that, for the most part, don't manifest in combat. The fleet illusion, for example, did what for Sadow when he faced off against Ludo? What powers did he use then in combat? I'm not discounting or lowballing them, but in order for me to agree they are more powerful than and can defeat someone like Dooku I need more combat oriented-feats.
He was in his meditation sphere when he employed the illusions, lesser force users such as Satal Keeto could project illusions of hundreds of ships without a med sphere as well. Kun being more powerful than these force users who could employ the force on such a scale would be well above Dooku, who has used much more rudimentary attacks on people who don't compare in power at all. Just because we don't see them utilize force abilities such as illusions in combat, they can't be discounted due to lack of exposure simply. The individuals Dooku regularly beats up (Ventress, Tholme, Kenobi, Bulq, Legends Vos), lack anything but the most basic of force abilities. If anything he lacks any showings comparable to Kun's accolade of being the strongest Ancient Sith, and being more powerful than the Jedi of his era as well. Dooku's not that unique in the grand scheme of things. Vader is a different beast he's got immense raw power, but Exar's knowledge of sorcery was stated to be beyond Vader's knowlege as well:
The dark knowledge of the Sith teachings died with Kun, it is extremely unlikely that any records survive, either on Yavin IV or elsewhere(Keep in mind that even Darth Vader, himself a Dark Lord of the Sith, did not know all there is to know about Sith powers.)
Also, Muur didn't stomp Krayt until Krayt was stabbed in the neck. And Nadd did that to a much weaker incarnation of Kun, certainly not of Dooku's level. The ton of rubble is a good TK feat but Dooku can and has performed feats like that on a number of occasions. Even Plo Koon can collapse caves with a gesture.
Muur was stated to be more powerful than Cade and Krayt during the time they encountered him which is a total mind****.
On Had Abbadon, in the Deep Core, Krayt confronted Skywalker a second time. But a third Force-user possessed powers that outshone them both. Karness Muur, an ancient Sith spirit, blasted Krayt with overpowering energy, sending him over a cliff to the rocks below.
-Source: Insider #113: Profile: Darth Krayt
-Credit to I_like_Shit
With Karness's power Vader mused he'd kill Sidious, and even Vitiate feared the Ancient Sith spirits like Muur as well. Its irrelevant if he was injured as he was already more powerful than Krayt as per the quote. Seeing as Krayt even as of this time can slaughter an entire ship of Vong soldiers (a force feat that is beyond anything Dooku can accomplish), Exar being the most powerful Ancient Sith would put him above either fo them. Karness alone would be more than Dooku could handle tbh