As we are into Buccaneer thread creep ....
When I and, I assume, BEagle first flew the Buccaneer, the only sortie that you ever flew with a pilot in the rear cockpit was the first sortie, FAM 1. With respect to normal instructional techniques, the QFI had only two options in this case, shout or eject (and the latter was threatened on at least one occasion)! For these sorties, some QFIs insisted on being captain. However, when I converted someone to the Bucc at Boscombe I flatly refused to be captain! If I didn't have a stick or throttles there was no way that I was signing for the aircraft. It is interesting that the first sortie on which you flew simulated asymmetric approaches, FAM 3, was flown with a navigator in the back, although in later years I believe that these were flown with a pilot instructor.
In a period of 18 months in the late '70s there were two engine failures on FAM 1s. The first was at high speed so it was not a problem. The second was a first tourist pilot on my course who had the right engine fail during the finals turn of a right hand circuit when configured such that a single engine capability did not exist (45-25-25). There were no engine instruments in the rear cockpit but the front seat was offset slightly left and the rear seat slightly right such that the back-seater could see some of the right instrument panel and the right console. The instructor was the USAF exchange pilot who saw the right engine winding down and just instructed the pilot what to select up and when, which he did, and a successful recovery was flown; an excellent response by both. On my FAM 1 I had an intercom failure and a QFI with a loud enough voice to shout audibly "Land off the next circuit". Fantastic times!
There actually was one twin-stick Buccaneer. When XV344 was configured to be the 'Nightbird' research aircraft for RAE Farnborough a stick was fitted in the rear cockpit to allow some safety pilot intervention. However, by the time I started flying it the stick had been removed, and I believe that other than during initial trials post conversion it was never fitted because of poor mechanical characteristics.