The Moose and Grandal parts could well happen. The Rays are a contending team so I don't see them moving Morton for prospects. An alternative would be to sign DK (probably a 3 year deal) or Hamels (probably a 2 year). Another alternative is to trade for a starting pitcher from a non-contending team such as Matt Boyd.
Kinda think the rotation piece comes from the group of Bumgarner/Hamels/Keuchel since it'd be nice to have two lefties in the rotation. Everyone (AA included) would prefer to have someone who misses more bats than Keuchel, but is it really that important given our infield defense? It would be downgraded a bit going from Donaldson to Moose, but it's not like he's a butcher over there.
If he's not going after a true swing-and-miss TOR guy like a Kluber/Morton/Snell type in a trade, those three probably all likely get in the $13-$15 million AAV range (unless someone like Minnesota steps up and seriously overpays for MadBum), and Hamels seems to be the best fit since he could probably be had on the shortest deal.
Rosenthal posed an interesting question this morning on Hot Stove - could the Cubs be considering trading one of Bryant or Contreras to try to get a SP? Would Theo and Jed consider Wright plus for Contreras? If we really aren't considering Grandal at all and they got an inexpensive rotation piece, the Cubs might be. If they gave the money they were paying Hamels to Grandal, moved Bryant to RF, and Baez to 3B they'd still be pretty scary (although the OF defense would be pretty weak).
If AA traded for Contreras ($4.5 million projected), signed Moose ($10 million), and could stretch the budget slightly, he could add Ryu AND Pineda to the rotation and have enough left to pick up another decent arm like O'Day for the pen for a little more than the $45 million figure being tossed around with Wilson, Weigel, Touki, Anderson, and Davidson in Gwinnett.