I don't know about the wimpiest ( aside from J Wellington Wimpy),
although I recall an English Ambassador to the USA , called Sir Crispin Tickell, which certainly tickelled me.
A senior officer I encountered in my Navy days was one Commander Robotham ---he insisted that it should be pronounced " Row Bottom", and thus became known to officers and ratings (enlisted men) alike as " Paddle Arse".
                Our very own Sir Ranulph Twistleton - Wickham-Fiennes is,I feel, possessed of a somewhat whimsical ,if not actually wimpish, handle ; the longest conjoined surname known to English heraldry is the magnificent ( IMHO) Temple-Nugent- Brydges- Chandos- Grenville . -----not bad, eh ???