Now here's proof that Nero is definitely Vergil's father, great video overall! I'd like to also point out that Nero's rawhide "Side Winder" move also looks like Vergil's Judgement Cut move so you can add that into the list if you want!
I know what u mean even though you worded that a bit off. But you know what they say like father like son. Nero learned how to fight from Credo, yet instictlinctivly he was able to adapt to his father's fighting style in some ways. It's in his blood of course the blood of Sparda.