? Thats exactly how it worked what are you on about.
Haki is means will power, so when he transfers his will to his sword its pretty obvious whats going on, what else can it be that zoro with a sword has sliced at leaves but its not been cut as opposed to a barrier on his sword. Are you suggesting his sword turned blunt ? it went through the leaves what ?
With luffy its clear what happens,
Hes about to attack clealry sees the future of what happens if he follows through with the attack and sees his arms chopped off and completely changes what he was going to do, he even fully comprehends that he was gonna lose his arms for sure, its not even about sensing. And one thing we got hammered into us with katakuri is the usuage of fs in conjuction with how calm you are. Which mihawk clearly points out.
Now on to the zoro part.
and here is the stephen paul translation of this scene
Excerpt: Zoro: {I dodged... this rock?! ...no. I KNEW... I KNEW the place where it wouldn't fall... My sword... Is under the rock there. I KNOW it...!!!}
During all this whole scene zoro is extremely serene and calm. Now fs you clearly see a picture about whats about to happen
like kata showed many times in wci for example
He has a clear picture of what happens.
(which as luffy showed vs mihawk and sanji in the next scene of this moment is subject to change depending on the actions taken)
Now zoro clearly says he doesnt dodge or sense anything. And as i stated earlier he was extremely calm, He not only knew where the rocks would and wouldnt fall he also knew exactly which rock his sword was under. This clealry points to like above with luffy and kata he had the scene play to him so he knew exactly what was gonna happen.
Its not sketchy at all it actually fits pretty well, do i believe oda had all the ins and outs of haki back then no not at all.
Its not an over complication at all.
At this point in the manga we have the explanations for acoa from hyou and fs from kata, both moments of zoro fit into both sections and follow the same guidelines as explained for each ability.
The first problem here is that you're suggesting that Luffy and Zoro displayed advanced forms of an ability they hadn't even trained in their most basic expression. Not only that, but Zoro actually mastered it to a point where he could use it casually (which he did). That's your first stretch.
Second, I'm not suggesting that his sword turned physically blunt. I'm suggesting that he chose not to cut the leaf and so it happened. That was the main point of that power, not covering it with a barrier from an advanced armament that has been shown to be actually an offensive weapon. The point of the breath of things, what is clearly explained in two chapters, is channeling your will to your sword and ultimately master it to the point of being able to cut anything and nothing at the same time. So no matter how sharp your sword is because you won't be willing to cut the piece of paper and, therefore, it won't. Not because you summoned an invisible armor but because your will wasn't to do so.
With Luffy it isn't clear what happens because future sight is an advanced power that he learned recently after spending two years training the basic form. You're trying to sell quite an unbelievable jump by suggesting that a Luffy who ignored the basics of observation, who hadn't even awakened it (and we saw what happens when you awaken it with Coby or Usopp), happened to see into the future even though that's a very advanced, rare power that only the strongest achieve. For all we know, that panel could be Luffy's thoughts on what would have happened if he had gone crazy (in other words, uncalmed) and attacked the World's Strongest Swordsman with such attack, or why not? The lecture that a glimpse of basic observation gave him on Mihawk's intent of cutting his arms.
And Zoro knew where the rocks would fall because he heard their breath. I mean, he explicitly states so, that the rocks had a breath to them like a sense of life (I don't know why you say that he "clearly doesn't sense anything", that's not the case at all). All of which precisely goes against how basic CoO and future sight both work, as the first doesn't feel inanimate things and the second doesn't sense but receives a detailed image of what's to come, hence why in your own panel Katakuri didn't understand why Pudding fell. That's also why he knew where his sword was, he could hear its breath, just like he could hear the palm leaf breathing or Bonez's steal body doing so. He wasn't seeing his future self picking the sword up or something like that.
It doesn't fit in any way possible. You're cherry-picking the commonality of being calm while forcing the assumption that they, out of the blue, happened to display (in Zoro's case to a certain control in next pre-timeskip arcs) the advanced forms of a power not only they hadn't awakened, but they were taught in their basic forms by their timeskip masters.
Zoro explicitly states that he was sensing the breath of those things, that's why he knew where the rocks would fall and where his sword was. This ability, more importantly, is directly related to the power of cutting anything but nothing at the same time since, as Zoro himself reflects, the power to sense the breathing is what allows you to perform such cuts. So apparently this advanced armament that Hyogoro explained (without Luffy ever thinking of "hurting anything but nothing at the same time", only punching harder) in the same fashion as Koshiro isn't armament alone anymore even though he was teaching Luffy advanced armament; it also requires a supposed observation that works in no way like any other explanation we've been given before nor any other usage we've seen (and no, future sight has nothing to do with sensing the breath of inanimate objects, which is what Zoro did as he explicitly stated).
Breath of things was clearly conceived as an ability of swordsmen who awaken the power to sense the breath of inanimate things (unlike observation, which senses living beings) and connect their will to it through the sword in order to cut anything but nothing at the same time (or, in other words, to perform a slash that won't damage a leaf but will cut through a rock). That's it. And I'll be even more concise: the logic behind armament, which is, a stronger armor grants more powerful attacks (as explained by Rayleigh), goes completely against how the breath of things was portrayed as Zoro tried to cut Bonez with harder and stronger attacks but all he needed to cut his steal was a specific quality slash that connected with its breath. The logic behind observation, which is, sensing living beings but not inanimate (hence why Fujitora or Usopp saw living auras or Enel wouldn't predict random punches), again goes completely against how the breath of things was portrayed as Zoro sensed the breath of inanimate objects (exactly that which observation won't sense, and in case you mention future sight, it doesn't sense but provides detailed images of incoming events).
Of course it will make sense if we keep it simple and think "hey, Hyogoro said the same as Koshiro and haki is will, so it makes sense that breath of things is advanced haki flowing through the sword!". Yeah, that's not the problem. Everything will make perfect sense as long as we focus on the things that support it and ignore the rest. The problem is the amou nt of things that won't hold up, the amount of incongruencies we have to ignore or explain with imposed reasonings that, for example, will require combining observation with armament even though that was nowhere to be mentioned or even hinted in Udon.
Zoro sensed the breath of things and therefore could slice through them. Zoro didn't slice the leaf but the rock because he channeled his will following breath of the rock. That's the point of "cutting anything but nothing at the same time", not some intrincate theory about activating and deactivating an advanced armament which produces an invisible armor that was clearly drawn breaking a stone apart just by touch when explained by Hyogoro. And that's the armor that won't damage a piece of paper?
And that's my last take on this issue. Oda retconned the power and now we need people like you or the original poster making up explanations to add some sense to such mess that will ignore the incongruences and will force scenarios like rookies with no undertanding of basic haki awakening advanced forms. Good luck with that, sincerely.