Previously, Napoli planned to sign Lukaku after Osimhen was sold, but Napoli are currently still sticking to their plan to keep signing Lukaku even though Osimhen remains in the squad next season, playing Lukaku and Osimhen may seem like a good plan but I don't think it will be effective Osimhen who may no longer play wholeheartedly for napoli again.
Antonio Conte feels more confident with Lukaku than Osimhen because he also wanted Osimhen to leave the team and if he didn't leave I think he will not give him enough playing time which will affect Osimhen's market value and his performance which will directly be against the club's will because they were expecting to cash out big in his deal. Therefore, I think Napoli will find a way of selling Osimhen because the player has also lost interest in the team which means keeping have no use for the team. The Napoli management will reduce the money if no team is willing to pay that amount and I am sure Osimhen will not go to Sausi Arabia.