Well, this was only a half serious suggestion. I love Cueto's impersonation of one of my all-time favorites, Luis Tiant. That said, it is absolutely not a "no f***ing way" suggestion.
Between David Price (at one year plus two-plus months) and Jon Lester (at two-plus months), the market for aces may have been set. If so, the returns have changed. It is no longer about major league ready prospects, but about major league proven players.
Price particularly seemed to bring back a lower than expected return. Drew Smyley is a nice pitcher but will not likely be a top of the rotation pitcher. Nick Franklin is probably a marginal major leaguer. The prospect appears to be just okay.
Cepedes would fill the Reds' desperate need for more offense in their pitiful line-up and a power-bat in left field to bat between lefties Joey Votto and Jay Bruce. They really need more on-base skills than Cespedes would provide, but he might be the best player from a team with a need of what the Reds need to move.
Cueto has one year left on his current contract and Cespedes has one year left. That part is a wash. The thing that handicaps the Reds is they have four starters plus Arnoldis Chapman scheduled to be free agents after next season. They want to be competitive and move forward while rebuilding their rotation. Homer Bailey will be back. Alfredo Simon may be re-signable. Cueto, Mat Latos, and Mike Leake will probably be too expensive for the Reds. They will need pitchers capable of filling in their rotation. They have Tony Cingrani and Robert Stephenson in the wings, but they will need more starting pitching depth. Allen Webster and Rubby De La Rosa may be the most major league ready the Reds can acquire.
Mat Latos might be a more likely starter to substitute in this deal, but I don't think he is healthy. He has had surgery on his arm and has seen his velocity drop this season.
We never truly know what will happen, but my suggestion was not a "no f***ing way" suggestion.