R2D2 is what you wish the CIA were like: all the hotshots get the glory, but when you look at it, R2 is what makes the whole thing work. Who projects the hologram of Leia? Who shuts off the crushing walls? Who finds where the teenie bomb is supposed to be dropped in the Death Star?
C3PO is more like the State Department. Of course, our State Department wouldn't be so twerpy and ridiculous. They are a serious, socially facile bunch.
On the other hand, C3PO would have gotten the Russian translation for "Reset" correct.