I really love this battle.
Dunno if Alucard would use his Mind Control in-character in a heated battle. I don't recall him using it in a serious fight, and considering Guts resists the variations of that, he might be able to ignore Alucard's mindhax, but take it with a grain of salt.
Alucard's 8-B is for his TK and going by the profile he's barely above baseline with 13 Tons. While if correct, Guts'd scale to 45 Tons, making him 3.4x stronger than Alucard's TK. The latter is also a glasscannon having 9-A Durability, giving Guts the opportunity to always land a critical strike.
The Dragonslayer is able to negate Regenerationn via injuring the soul, which Alu can't resist so his Regenerationn is getting nulled here.
Guts' also faster having HHS+ reactions (Mach 65) versus Alucard's HHS (Mach 33), meanwhile Alucard's Hypersonic+ movement speed surpasses Guts' Hypersonic movement speed. It's really funny that one is faster than the other in two different ways.
They are starting at 4km considering the vampire has the advantage here, so he has the option to spam the bullet hell meanwhile Guts has to close the distances. Considering he has a 2x speed advantage and he's starting with the Berserker armor, he won't have much problems doing so.
With the Berserker armor Guts is a monster who won't stop, while Alucard's stamina is depleted by the fact that he won't be able to regenerate from soul-injuries.
Both are highly skilled opponents. Guts deals with characters similar to Alucard in the sense of being stronger than him and always aim for the head to finish the battle as soon as possible, while Alucard plays with his enemies before crushing them after stomping their hopes. His mindset is a severe disadvantage, even more when we consider that Alucard believes just a human should kill him. Well, guess what, Guts is a human and he's trying to kill him. He won't hold back, sure, but I don't think he'd struggle to survive and would die with a smile on the face.
IDK how Alucard's abilities would interact with Guts so feel free to correct me if I'm wrong, but I'm leaning towards Guts for superior AP, Durability, Speed, Regen Negation, Stamina and Mindset. This fight is so cool.