None of these top Generals were really top Generals yet!

Patton was leading the 2nd Armored Division not even a month earlier in the Manouvers in the South when Pearl Harbor occured, and was only the rank of Major General.

Eisenhower was a Brigadier General at the same maneuvers, and was evaluating performances of hitherto new units; such as Parachute Infantry Regiments and the aforementioned Armored Divisions. He was working closely with the staff of the V Corps, if my memory serves.

Both had been echoing the Rhetoric of FDR and other Top Brass for a while now, from all that witnesses and biographers have to show us; Patton actually said that the entire Army would be at war soon (with a German foe, however) and that the maneuvers they were participating in would be the 'last real test before combat' (Houston, Ed: Hell on Wheels). Eisenhower as well was evaluating units viz. performance observed in France and Russia; preparing the US Army for war with a European foe. As was General McNair, and so on and so forth at the Army Groud Forces.

Pearl Harbor I'm sure would've been as much of a shock and outrage to them as it was to every other American at the time, and definitely brought them into the war a bit sooner than they may have hoped in light of the rapidly expanding US Army.