If you're using the 1951 election as evidence of Churchill's post-war popularity, the fact that a larger number of people voted for his direct rival in that election is very relevant. It directly refutes the argument you were trying to make by referencing it.
Unless your argument was that the number of seats a party leader won in a FPTP election is a better measure of their popularity than the actual number of people who voted for them. But that would be a ridiculous argument, because by that metric Churchill was less popular in 1945 than Corbyn was in 2019.