We got the international slots we needed for next to nothing. We are trading small amounts of TAM/GAM and useless late round super draft picks for them. Your saying you'd rather hang onto those minimal assets than adding depth and rolling the dice to see how a young player super cheap player will develop. Depth we in fact needed this season. When Mata was in international duty and Allen was hurt/suspended who plays LB in your proposed scenario without Martinez?
Iraola? Mena? Bravo? Hernandez? You are talking about a third choice left back. You can even play a back three and play Harrison as a wing back. I am sorry to disagree with you, but international slots shoudl be used for players who play a part whether starting or on the bench.