It's tough because Ronaldo doesn't have the agility that he used to have. From the left wing he used to be able to destroy defenders off the dribble with explosiveness and power. He still has power and pace but he has lost some of that agility. So I guess the idea is that playing him as a striker rather than LW allows him to poach more, and puts him naturally in central spaces where he is dangerous.
The narrowness is a problem, and it puts a lot of pressure on the fullbacks. It would help a lot with an elite CAM though, adding a bit of unpredictability.
https://en.onefootball.com/the-false-ten-explained/ A false 10 would probably be useful. Unfortunately Bernardeschi while mobile and energetic is VERY PREDICTABLE. It would also help if our CMs were more mobile as well.
We played a 4-3-1-2 with Allegri before but our CMs were Pogba, Vidal, Marchisio. Those players had the mobility and work rate to cover for fullbacks (Pogba less work rate), and were comfortable adding width as needed as well. Khedira is not that. Matuidi is almost that except he is poor on the ball. Ramsey if healthy could be that.
Honestly if Bernardeschi had a bit more creative flair,
Matuidi was better on the ball and Khedira's legs still worked, I think the predictability problem would be gone. Also Alex Sandro isn't your classic uber offensive fullback. He's great but if you're looking at just attacking ability there are better suited for adding width. Although I don't think it is worth it to sacrifice Sandro's all around ability for a guy who might be better going forward but is a liability defensively (ala Marcelo). It's so annoying that at first we had an elite midfield with average strikers, and now every position except the midfield is elite!