The combination of these two players in the attack will be a disaster to any club defense if they can play as one with a strong bond. Mbappe and Vini are irreplaceable and that was why Ancelotti went for Mbappe when he was in PSG. Alonso will work on them and make them play with humility so that they can put in their best performance when they are on the pitch.
The condition of if they can play as one with that bond is where the challenge lays because both players are yet to blend well and build that bond or chemistry between themselves since when they had Ancelotti as their coach and now xabi, they are both very brilliant and good players but until they build that team work spirit in the. Which xabi is trying to achieve, they continue to make lesser impact than they would have done together.