On the bolded part - I was discussing with another user who concluded Antony is "far more dangerous" than Sancho what is definitely not true.
Antony is getting the numbers just like any other attacker would be getting playing for United. Unless you're Wout Weghorst, you will be scoring/assisting in this team.
On the rest of your post - I fully agree. "Beyond numbers" there's little to argue about, Antony is clearly much more useful for us now. I don't think it's an interesting point to argue, but it will be more interesting to see if IN THE FUTURE Antony is the kind of winger we really need. I have serious doubts about that.
On Sancho - I would look to offload him this summer. It is not clear what he brings to the team that others don't. He's unfortunately not a good fit for Premier League. And I think we can get decent money for him, while I don't believe it's the case for Antony (who's probably also on much lower wages).