"to say that decision making is synonymous with problem solving is to understate the complexity of the former

Answer 1

Is this a rhetorical question? As I understand the logic, you're making the point that, to say traveling is synonymous with arrival is to understate the complexity of the later because traveling doesn't guarantee you will arrive. Makes sense.

Answer 2

Decison making does not equate with problem solving. To make a decison is an expression of will, it does not require that the problem is solved by the implied action. The statement is therefore logically correct.

Answer 3

Agreed - as a generalization.