Buffet has a pile of dollars. He wants the value of those dollars to go up. Cutting taxes has made the dollar go down. Clinton/Rubin raising taxes made the dollar go up. This is the way it always is. Look at the advice the IMF gives to Argentina or Russia when their currency is declining. Raise taxes. Each and every time.
Lowering the value of the dollar as Bush did was exactly the right policy. A sky high dollar was killing American manufacturing, mining, and agriculture. It was the only way. There is a time and place for every style of fiscal policy. In this time and place, Bush was 100% correct and Buffett 100% wrong.
Nonetheless I bet he will give Arnold good advice. The Governator of Cali has nothing to do with the level of the dollar. Buffett will tell Arnold to do what he has done to every business he has managed or advised. When you are in financial trouble, cut expenses as a first step.