Spurs need this year's Llorente above all. Liverpool have four relatively proven goal scoring forwards. Spurs have one, a thirty year old who relies on pace and lacks two fully fit hamstrings. In addition to a veteran hold up player, get a second goal scorer/creator as another option and injury insurance. They'll both get minutes in any games Spurs need goals.
Effing with the starting 11 at this point is fixing what ain't broken. The chances of screwing things up are a lot better than making an improvement. For an example of that, see Spurs forwards and buying Richarlison last year. I'm actually skeptical of replacing Sarr with Bentancur for the same reason, despite Bentancur being class and Sarr being the second least impressive of the 11. Sarr is playing well overall, and is a very unusual player. He has his biggest impact anticipating and preventing or creating goals while often racing long distances. I've never seen anyone with his style. Do Spurs really want to risk removing it from the mix, at least as long as things are going well? Bentancur's role overlaps more with Bissouma, IMO, so adding him and subtracting Sarr really changes the nature of the team.
As to the rest of the squad...is it really wise for Spurs to get players better than Hojbjerg, Skipp, Emerson, Davis and potentially Dier to sit on the bench and become next year's deadwood? Can Spurs actually improve on them without being able to offer a starting position? It's not like there are many games to go around this year. To me, it's get one proven veteran goal scorer who's also a hold up player, plus a second goal scorer/creator.
Very much agree - particularly with your Sarr comments. The Bissouma/Betancur rotation makes much more sense, especially with the former seemingly more familiar with cards than Cool Hand Luke! 
