Both of them neg Mid-Godly, so I believe you're talking about Glencalibur, right ?
Yeah, that's a trouble, however Valcua doesn't resist Alucard's Soul Hax which is also in character, but most importanly, Valcua is very overconfident, so I dunno if he's going to yeet Alucard with his sword right at the beggining, add this to the fact that Alucard have supernatural luck and things can change
I doubt that Alucard would start with his soul hax. He would start with his sword, and in a sword battle, he would have trouble cause glencalibur negs mid-godly regeneration
And yea, Valcua is a little overconfident, but not much. His first move against the two nobles that were protecting Sue and his brother was to strike them with an attack that was clearly aiming to kill (he cut Mirand in half If I remember correctly), even with them being much inferior.