This makes a better team with balance in the lineup. Walker is 24 and has done nothing to this point with 4th OF potential. The guy we got back is 24 and has already hit around 80hr's in the big leagues and still has unlimited potential according to most big league guys. Worst case scenario he doesn't pan out and you go get someone next off season. This is a low risk high reward move.
I said it yesterday, for rebuilds to work you have to take chances on guys and some of them have to pan out.
Cubs are an example with their moves for Rizzo, Arrieta, etc. ....
Every rebuild must have surprises.