User blog comment:B214/Question and Answers 4/@comment-120.161.1.224-20141003041806/@comment-16281343-20141003081458

IMO, they will receive a set amount of power that is equivalent to the boost in their abilities when a person is reincarnated using a Queen piece.

Note: I'm only talking about base stats here, not including their potentials or any outside forces.

Example:
 * 5 Pawns - promotes to Queen will receive +10Power, +10Speed, +10Magic
 * 1 Pawn - promotes to Queen will receive the same boosts.

So, who will be more powerful of the two? With regards to their base stats, the 5 Pawns will be since his stats is more higher in the first place.