While I haven't read a biography on Beatty, I don't think he had what it takes to be Prime Minister. The Interwar Years would have been interesting since I feel that he would have been a great proponent of the Fleet Air Arm - or at least wrestling a portion of it back from RAF control. Realistically much like Sir Roger Keyes he would have been brought out of retirement at the outbreak of the Second World War. The Admiralty may have flashed a message to the fleet 'Beatty is Back'. Perhaps he could serve as First Lord of the Admiralty after Churchill moves on to No. 10?