Bruno would be a disaster in that position. It perhaps work in a 3 man midfield, with the extra 8 or 6 able to assist in the shape and structure similar to what I think was the most balance midfield in recent seasons in Herrera, Pogba and Matic but if it's the 4-2-3-1 he would be a weaknesses in possession.
I would actually be interested to see if Sancho could play as a 10. In the City youth team and early stages of his Dortmund career he was for all intent and purposes a direct winger but I think perhaps playing with Hakimi made him revert to being a wide playmaker (give and go, consistently dropping into half spaces). I've yet to see Sancho really break the lines with his passing but he looks like a 10 far more than a winger nowadays.