The Astros lost Keuchel, Morton and McCullers for 2019. The only returning starting pitchers are Verlander and Cole. Yes, they have McHugh and Peacock capable of starting and Whitley and James in the wings, but they are losing 3 starters with big production and replacing them with guys less likely to succeed.
The Guardians dealt off Encarnacion and Gomez while bringing back Santana, which is a definite downgrade offensively. Add to that the losses of Brantley, Miller and Allen and I doubt the Guardians are gonna scare the sox, even though they still likely are the best team in the central.
The only team that hasn't lost much is the Yanks. Yes, Britton and KRob are still on the market, but the pen has been a significant strength and still is with the loss of those guys. We added Paxton which will make our team far more lethal. If we sign one pen arm and then nab Machado, we will be significantly improved.
The sox are still the champs, but their entire loss of a pen is going to be tough to replace. Right now, I have a hard time thinking the sox can repeat with the sieve in the back end, but I doubt the sox don't lock down at least the closer spot