Like I said, I don't think the holograms should play all the songs with Paul, but rather something more bittersweet and beautiful. Here's my idea.
The stage lights go out. About ten seconds later, two person-shaped lights appear on the side of the staircases. They fade in to reveal John and George, walking up to centre stage. The lights in the middle flicker on, revealing Paul and Ringo. The holograms stand around them and they all smile. Paul sings a line of a song (let's say Hey Jude even if it is the early Beatles as holograms taken from