By the time Macho becomes a FA, Porcello & Bogey will have one year left, so it's not so simple as swapping contract costs for Porcello & Bogey.
Yes, the money in 2019 will be about even, and I'd much rather have Machado & Wright than Porcello & Bogey, but 2020 and beyond will be very costly.
Yes, there will be some money, but much will be eaten by rising arb costs of Betts, JBJ, Vaz, ERod and others.
I'm certainly interested in Machado, and I'd be willing to pass on JD, if it meant we got Machado.
The other part of your suggestion, is what could we get by trading Bogey & Porcello after 2018? Probably something very special to add to Machado's gain.
(I'm not against the idea.)