A midfield with Busquets, Nico, Puig would be very stable and at the same time dynamic. Yes Pedri could play as a winger or something also. Did Puig and Nico play alot together before?
I think Nico isn't quite as elegant and flairy as Busquets at DMC, but he makes up for it to some extent by being faster, stronger, more distinctive defensively, and he has a bit longer range in his passing (mostly a question of flavour). He also brings the ball forward sometimes just as calmly and explosively as Frenkie does. I can see Koeman really liking this player, and I do as well.