This seems like the trouble in this debate. We don't really know if the team is doing exactly what you asked for - have a plan A, B and C. Or had no back up and ended up in a mad scramble.
Isn't it possible the team had a first choice, let's say Carlito. They can't get that deal, for whatever reason. Then they have a number of options still on the board, the best of which is Kamara. They pursue him but can't compete with Chinese dollars without going DP and they aren't willing to do that. So he falls through. Now it's late in the window, but they still have their list, the best of which at this point is Heber. They go for it and get him.
They did exactly what you are asking for. Maybe there was even overlap in the negotiations with the three players. Maybe there were 10 other players in negotiation that we are now walking away from as Heber comes through. They had a plan A, B and C, and they executed on that. But from the outside we are calling it a panic buy.
I find that at least as plausible as the claims here that they had no plan B and started over from scratch at each stage.