Okay, I'll try to analyse this, but imma already say that this is a conceptually awesome match. Guts is one of my favorite characters ever from any piece of media (And Berserk in general has a soft spot for me) and Yujiro is, well, Yujiro. I love how goofily badass he is.
So, AP. Yujiro has 4x the raw strength advantage, and this gets way more ridiculous if he uses his Demon Back (Allows him to one-shot and play with people who were otherwise equal to him and even taking very little damage to very strong, serious strikes of his base form) and techniques that amplify that, which are many. Guts does balance that a bit by using a sword, which minimizes contact area a lot and distributes force way better, and the Dragonslayer itself is, if I'm not mistaken, quite a bit stronger than Guts is, so this is helpful. Same goes for durability, if Yujiro fully employs his skills he can vastly outclass Guts, but at least Guts can block extremely well with the Dragonslayer and has also some incredible willpower and pain tolerance that helps his toughness. In LS there is no contest, Yujiro is both the vastly superior grappler, has powers that makes his grappling do insane, impossible stuff and has a vastly superior LS. I won't say that Guts is helpless, he has the tactical knowledge, toughness and skill to make the best of a bad situation (i.e., using his arm cannon when thrashed around by apostles stronger than he is) but it is a very bad disadvantage for him.
I'll already say that Yujiro should be about as fast than Guts, if not faster, and certainly way faster with techniques. Base Yujiro scales as significantly above the speed on his profile, and he continually grows stronger and faster over Baki, and not only that, but his Demon Back also amplifies his speed, and he has techniques that are pretty much insta-blitzes for even someone on his level. I'll be fair and say that Yujiro isn't one to abuse said techniques, especially when it ain't needed, but this doesn't look good. Strangely though, I feel like Guts is way more mobile than Yujiro; it's less that Yujiro can't do the stuff Guts does, but he simply does not do that in a fight.
Skill-wise, I'd like to comment, as I always do my apologies for being boring that skill isn't a simple matter. I agree that, yes, in general, Yujiro is vastly superior to Guts (and anything in Berserk really) in CQC and in direct combat. Yujiro has command over his own body, precision, technique, coordination and many other things far above anything ever shown in Berserk. However, there are aspects one ought to consider. First, Guts' tactical skill outclasses Yujiro. As in, usage of the environment, tactical thinking, making decisions based around unorthodox knowledge of otherwise non-combat things, Guts has consistently shown to be an excellent tactician. Yujiro is great too, and I don't really doubt he can do many of the things that Guts' can, but here's the thing: Yujiro simply doesn't care to do that. His fighting style does not encompasses that sort of fighting, so much that Gaia was thought (possibly with reason as Yujiro has very few feats in that sense) to have superior tactics than him, because he doesn't need to. This time he'll be fighting someone that isn't far off of him, and that is not only proficient at that sort of fighting, but actually thrives on it, and Guts is used to deal with opponents stronger and faster than him. Yujiro isn't used to dealing with people comparable to him that fight like, say, how Gaia would fight. The closest to that was Musashi, and he is still way too straightforward compared to Guts.
The second thing is that skill isn't a simple measurement that one can say to be superior to the other and there's that. There is much to say here but the argument is already too full to go on about it, but skill is infinitely complex and has a lot of push and pull. Even vastly less skilled foes can pull surprises against superior opponents, or even dominate them if their specific skillset has good counters to the more experienced foe. Now, I agree that those are the lesser probabilities for a good reason, but the ebb and flow of a fight isn't simple enough to allow a simple analysis of skill to grant certain and absolute advantage.
In powers and abilities, there are many interesting aspects and things to follow on this. The first one is that, thanks to Guts' armor, he might actually be protected from many of Yujiro's skills to a certain degrees, making pressure point strikes, strikes that rely on hitting the skin (Benda) and many other things non-effective. There's also the fact he'd resist Yujiro's aura and effects, and brush off any pain. His forced regeneration also helps him on staying on his feet. However, again, Yujiro's skillset is absolutely ridiculous, nothing on Guts' profile that can be effectively applied here is new to Yujiro, and he has several ways of taking care of Guts' attacks while the inverse is harder. Not impossible, but harder.
I believe Yujiro should take this with high difficulty, but it isn't impossible for Guts to win.
