Is there anyone younger who would partner perfectly with Ronaldo in your opinion?
Not really, people take for granted how unique Benzema is, and what a genuine top player he is, despite some flaws. He is just an excellent well rounded real quality attacker.
Or actually closest one to do this role almost as well next to Ronaldo is Firmino (more hardworking and more natural playmaker), but we wont sign him (and we shouldnt if we have Dybala, who is ridicolous player, doesnt have the box presence of the other too, but has excellent understanding with ronaldo). We really need just a well rounded backup CF for now, preferably someone technical enough to hold up and combine with others and have decent presense in the box.
If we cant get that, we need attacking box to box CMs, genuine top ones, that blitz into the box the times dybala drops deep, or Ronaldo drifts wide.