Firstly, I'll say Haki is incredibly inconsistent and a terribly explained power so these are our attempts at interpreting Oda's awful writing. Now that the disclaimer is out of the way: ACoC is not just no-touching. ACoC is an amplifier that can either touch or not touch, it depends on whether the user has barrier haki and wants to apply their CoC to it. ACoC can also act as a steroid to barriers - take a CoA barrier and add CoC, now that barrier grows even larger because you added more Haki to it.
ACoC users can 'not-touch' with both level 2 and level 3 CoA. E.g - Zoro can create barriers if he wants to but that's counter-productive for a swordsman whose goal is to cut you. Shanks' Kamusari's blunt force effect leads me to believe he used a CoA barrier with it.
Furthermore, you can also use level 3 CoA + ACoC and still touch. E.g - Kaido confirmed G5 Luffy is using CoA + ACoC yet Luffy isn't creating any barriers (I don't see why Luffy wouldn't be using ID CoA here). Luffy then decides to create a barrier for Bajrang Gun.
Kaido and Yamato don't have level 3 CoA, that's why Yamato couldn't break her chains. But they could apply ACoC to their barrier haki if they wanted. Through Law, Oda likened Luffy to Rogerbeard so the confirmed users of level 3 CoA thus far are Roger, Luffy, Whitebeard, Big Mom and Rayleigh. Garp and Shanks are likely users too.
What Garp did with Galaxy Fist is make a huge CoC-imbued barrier. So it could be but may not necessarily be level 3 CoA. It could be level 2 CoA with a shit ton of CoC, who knows. What Zoro did vs King is apply CoC to his already CoA coated swords - this injection created an instantaneous barrier that pushed King back. Zoro is the perfect example of characters who can create barriers but choose not to.
Kaido never made a significant barrier without clashing with Luffy which leads me to believe he doesn't bother 99% of the time. Hell, he might've just been clashing with Luffy's barrier, making it look like there were two barriers for some of them. So without the visual indication nor indication from other characters, I can't claim Kaido is an ID CoA user. He had enough chances to prove as much.
Point is, this whole touching/no-touching thing is largely insignificant and not something to look so hard into. If a character is using level 3 CoA and we need to know, Oda will make it clear somehow. All that's important is the sum total of your AP. A barrier-less ACoC attack can be levels above an ID CoA barrier + ACoC attack, it just depends on the sum total of Haki + strength you put into the attack. See Luffy's base ACoC punches vs Paradise Totsuka.