I really doubt that trade is going to make it through. You are getting a former top 10 fantasy player who still hasn't hit his prime plus two elite prospects at thin positions. I've been playing in 20 team dynasty leagues for 10+ years and I've never seen that much elite young potential given up in one trade.
Scherzer K's a lot but isn't an ace and Walker doesn't have that much value. At this point Perez is worth less long term then either Machado or D'arnaud as well, even if he starts the year in the rotation. I see it as Upton Scherzer + Walker and Machado alone Perez + Sanchez. I don't see anyway that trade gets accepted and survives the veto process.