The evidence suggests that General Wavell is largely to blame for the British collapse in early 1941. Churchill has a good responsibility, as well, but Wavell essentially saluted and agreed to measures that were totally destructive. A better man would have resisted Churchill's demands, and Churchill would have backed off (at least that is my reading of Churchill's writing). Wavell was used to taking risks and hoping for the best outcome. He had been lucky up until February 1941, when events took a turn for the worst, with Rommel's arrival in Libya.
Wavell did have the advantage that many of his personnel choices worked out well. He was also a good planner and administrator. His successor, General Auchinleck, seems to have been inept at choosing personnel. Auchinleck's main abilities were as a field commander, not as planner or administrator. That the latter topics worked as well as they did was more due to having a competent staff.
In any case, by the end of May 1941, the British were on the ropes in the Mediterranean theater, even while East Africa was wrapped up successfully.