Griezmann and Messi shouldnt play centre forward though. Fati doesnt look like one either, no idea what you are seeing in him for that position. Hes a classic modern winger. Maybe in a few years if he bulks up enough and improves his holdup play, but probably not for the next few seasons.
That leaves Suarez for the centre forward spot and makes the rumours that we are looking for one very credible. Other than that "rebuilding" our defense sounds a bit too dramatic. We need 1 centreback at most (depending on the developement of Todibo, Araujo, Umtiti etc). For the midfield spot I would be very content with 1 decent physical midfielder.
That are three transfers with one very expensive one (Martinez). That sounds kind of possible if we get rid of Coutinho and maybe even Dembele. Would be nice to see Messi as a 2nd striker behind two mobile forwards (Lautaro, Griezmann) as well. Could be a good way to get Messi off the wings (hes abandoning anyway).
-Fati has been a hybrid no9/LW during his youth career. He isn't that fast for a winger and he really looks more and more like a number with mobility. He isn't a classic modern winger at all IMHO
-What do you exactly purpose for Messi and Griezmann to play? I didn't say they play center forward. I said "all play inside" which is true. The last thing we need is anther attacker who doesn't play on the wings. It is a recipe for disaster.
-One CB at most? For real? Pique is almost 33 and will be 34 by the time knockouts of next season CL starts. Alba will be 32 at same time Lenglet is acceptable starter at most but preferably 3rd option. Umtiti is ruined by injuries. Todibo and Araujo are few years away.
Alba has 2 more seasons at most as a starter, and we can't wait to replace him and Pique at same time, for luxury signings like Laturo. We need a starting caliber CB at least and may be one more if we sell Umtiti. Nowadays to get a world class CB will cost anything between 40-80M. That is already an expensive transfer out there.
-Midfield need a new 3rd starting player, with Vidal and Raki most likely to leave and the need to bench Busquets, again we aren't gonna find a bargain CM easily.