How fair is the claim that most Churchill ideas were unworkable?

Is the claim that only about 10 percent of Churchill's ideas were workable too harsh or too lenient?

The percentages are not endorsed. The answer distinguishes serious proposals from passing remarks and stresses Churchill's role as a champion of other people's ideas.

The question suggests that 80 percent of Churchill's ideas were rejected immediately, another 10 percent received brief consideration and only 10 percent were workable. The answer does not validate those figures. Counting every passing utterance would produce a different judgment from examining serious proposals. Churchill also championed ideas supplied by others, so authorship and political support need to be distinguished. A memorable complaint written by a frustrated subordinate is not a reliable statistical account on its own.