Sarah has more relevant (executive branch) experience than the other 3 combined.
Senatorial experience is counter-productive. If you have ever witnessed what occurs when the lawyers take over and run a business you will know what I mean It ain't pretty.
Our country would have been better served if 2 governors were competing for the White House, such as Richardson vs. Romney. I am not endorsing either one, mind you. Just the concept that governors are in general much better prepared than senators to handle the position.
Palin/Jindal 2012 ...
Eisenhower: military general officer, university President
Kennedy: Congressman, Senator
Johnson: Congressman, Senator, VP
Nixon: Congressman, Senator, VP
Ford: Congressman, VP
Carter: Governor
Reagan: Governor
Bush I: Congressman, Ambassador, CIA Chief, VP
Clinton: Governor
Bush II: Governor
So, kind of a mixed bag as to which makes the better (successful) President. But, on balance, I agree with your point about governors having more executive experience than Senators.