This summer seems absolutely all over the place. Dembele, Raphinha, trying to hijack Richarlison then on to Sterling. No new leading CF, fishing around Ronaldo (who has only just suggested he wants to move which again shows there’s not been a plan at Chelsea prior to that), no new top CB to replace Rudiger. Linked to De Ligt who snubs a move immediately now Nathan Ake who must be pretty uninspiring as an alternative. Thiago Silva hangs up his boots next season too which presents another headache if they don’t buy well in that area now.
I don't know where to begin but there's a lot wrong with what you're saying.
Sterling has been Tuchel's top target for this window all along, way before any links to the likes of Raphinha or Richarlison ever appeared. From the start the plan seems to have been to sign Sterling as well as one of Raphinha, Richarlison or Dembele to replace the outgoing Ziyech (AC Milan) and basically Lukaku as well, given Havertz should play up front which frees up space for another new player behind him. Sterling looks to be in the bag but now if/when all three others are busts, it remains to be seen if there's an alternative plan or maybe just give another shot to the likes of Pulisic and Werner?
The Ronaldo links I'll give you. Boehly is after all an American and hugely marketable big names will surely interest him, so when it first started looking like CR7 is looking to leave your lot Boehly started getting intrigued about the idea and had some preliminary discussions with Mendes. His football knowledge is probably too limited to understand what a bad fit Ronaldo would be for Tuchel's team, but luckily for us he's given Tuchel the last word and if he doesn't want Ronaldo they're not even going to try to sign him.
As far as the CB situation goes, the plan has been to sign
two new defenders this summer to replace Rüdiger, Christensen and Azpilicueta. For the RCB slot the early top target of the previous board (Marina) was Jules Koundé who came very close to signing last summer already, but when it became clear last month that De Ligt is looking to leave Juventus the club paused talks with Koundé and shifted their focus to the Dutchman. De Ligt now looks like it's going to fail so maybe back to Koundé it is?
The pursuit of Nathan Aké has always been a separate idea from MDL/Koundé deals and he's being eyed for the LCB role, for which Tuchel seems to now want a left footed defender to replace Rüdiger. It also looks like the 19yo academy graduate Levi Colwill could be staying this season, he's another left footed CB who spent the last season on loan at Huddersfield. I don't necessarily think Aké is good enough to start for a team aiming to win the big titles but for the right price it could be a decent deal because the young Colwill is a very, very promising player and I wouldn't be surprised to see him overtake the position in the near future. That doesn't happen if a world class player is signed for the LCB role and in that case Colwill would go the way of Tomori, Guehi, Livramento etc. and look for a regular spot elsewhere.
Obviously there's still a lot to do and it can easily all go tits up if there are any more setbacks but at least for now I'm not in the slightest bit worried about the transfer business of Chelsea this summer and I can still very much see a plan in motion. We'll see near the start of the season how it goes.