I'm sure Perez still wants to find a replacement for Benzema, so far the vacant Real Madrid shirt numbers are number nine and number twenty four. I agree with your opinion, Kane can be a short term solution and Kane's type of play is also similar to Benzema if Firmino is more of a back-up player because this year he is 32 years old. while Real madrid already has Joselu and Brahim Diaz so it's possible between Vlahovic / Osimhen.
But Imo, for Osimhen himself he can only adapt after one season at the new team, if Vlahovic can immediately adapt easily to Ancelotti's tactics. But all of this depends on whether Mbappe wants to sign a deal now or next season when the contract runs out with PSG. What is clear is that Real Madrid cannot just rely on Joselu or Alvaro Rodriguez because the Real Madrid squad now needs mature players who can be a bridge for young players.
Of course, Perez must want to sign a top striker for their main striker. After Benzema left the club and joined At Ittihad, Real Madrid has no striker. There was a rumor Real Madrid negotiating for Harry Kane, but I am not sure Real Madrid is still interested to sign him now. Recently, we heard that Tottenham management sets Harry Kane's price is about £200 million. I thik Real Madrid doesn't want to pay Harry Kane at that price, it is too expensive for 29 years old striker. Moreover, Harry Kane's market value is actually only about £90 million. It is a bit strange that Daniel Levy and Tottenham management wants £200 million for Harry Kane's transfer fees. So, Real Madrid should look for another striker, Osimhen or Firmino is still available on the market. I believe these strikers will be much cheaper than Harry Kane's price (£200 million).
Check this: https://www.express.co.uk/sport/football/1777222/Tottenham-transfer-news-Daniel-Levy-Harry-Kane-Real-Madrid