From what i have observed. Sancho has world class skills. But Chiesa had top mentality and top hard work ability, as McTom, Bruno as Rashford. Chiesa has same mentality and fighting spirit as those 3 players. Chiesa is not a mood player. Chiesa always give 100 and is aggressive as McTom.
In an ideal. I would buy both. Place Chiesa on the left, then move Rashford back as CF. Then United dont need to look after a new really good CF. United have already a really good CF, A Vardy type of CF in Rashford. A hard working and aggressive CF like Vardy. So that CF problem will solve. And Bruno shall play as a free nr.10. It mean United will only use one CF most of the times. If two at the same time and Bruno deeper as nr.8 in need. Then you Rashford, Martial, Greenwood and Ighalo to chose from.
Chiesa versatility will give United many others alternative options.
A really strong line up:
Sancho/Chiesa - McTom - Pogba/Bruno - Chiesa/Martial + Bruno + Rashford/Martial/Greenwood
So sum. Chiesa is not as skillful as Sancho. But from what i have observed. I rate Chiesa mentality above. And as this moment. Chiesa is a half level above James, too be honest. And playing with teammates like Bruno, Pogba, Rashford and Martial. I am sure Chiesa will score many goals and assists too. Chiesa does match Bruno, Pogba, Rashford and Martial skills level. But only the young man Jadon Sancho football skills is above. His feet are really fast. World class skills.
So Sancho and Chiesa are two wingers I really like and enjoy watching. Chiesa was good playing for Italy U21, with Kean and Spain Fabian Ruiz. But naturally Italy U21 few years back in time was a lot better than Fiorentina right now. It made and helped him to doing well. The level of your teammates count a lot, on your performance. Just like you see with Bruno. He lift everyone’s performance. Now, Bruno is here. He will help Chiesa impact and performance too. Not only Bruno, but with a ready others good teammates too.
So the scenes are already set up. For both of Sancho and Chiesa doing well.
Compare back to the days. When all of Kawaga, Di Maria, Falcao, Mikhitaryan. All were struggling because they came at the wrong time, where United were struggling as a team and the way down. Now, the United ship is steady on the way up now. So the signs are clearly now.
A central spine with. Maguire if he hit the best level of CB, McTom CM, Bruno as a free CAM and Rashford back as CF. It is a really strong central line. A key factor for a successful team. Adding with Sancho, Chiesa, Martial and Pogba if he stays for many years. United future will look really good. It will help United new really good player a lot. They are joining a future winning team. You meet top aggressive and hard working players like Rashford, Bruno, McTom, Bissaka and Williams. It will not be easy to meet them.
In the end. You dont need to be a top football coach or expert to see it. That what will happen if United get Sancho and ideally Chiesa, to move Rashford back as CF. United will become a really good and strong team in the future and years to come. But if Sancho choose to stay with Dortmund for another season or another club. Chiesa will be another RW and versatile attacking options. So exciting future to come. United are not far to become a complete team now.