Consideration of changing market conditions that can lead to a switch between timeframes of the highlighted goals. Another thing that comes to mind is that most goals may be stretched long to also stretch the investment requirements. Therefore, to add to your analysis, a significantly higher budget would be required to be allocated toward what now has become short-term goals depending on how bad the client wants it done in a short period of time. I think there is no easy way to explain this in a polite way but like every business the client would expect nothing less and should only consider switching their goals if they have a solid reason behind their decision.