Astros currently have Myles Straw as projected to play CF. If he's the 2019 version, you go with him over JBJ. If he's the 2020 version, you go with JBJ.
They have a very clear need at CF though as there is nobody behind Straw that can field the position. As they are more likely to compete, they should be the ones to sign JBJ.
JBJ to the Stros?
Dyson to the Sox?