Well, basically you're agreeing that Mosley would have been trounced if he did put up candidates in 1935, so I don't see how he could have become PM. He had had four years since the founding of the New Party to organize an electorally viable party and didn't do it.
IMO George (not "David") Orwell was right to say that Mosley a
s a Fascist was devoid of ideas, mindlessly borrowing from Hitler and Mussolini, ignoring that a successful fascism must rest on national sentiment.. This is a different question from whether Mosley was devoid of ideas back in his Labourite days, but even then his ideas seem to be to be borrowed (largely from Keynes). Orwell's anti-fascism did not prevent him from recognizing insight in Hitler and Mussolini ("One cannot see the modern world as it is unless one recognizes the overwhelming strength of patriotism, national loyalty. In certain circumstances it can break down, at certain levels of civilization it does not exist, but as a
positive force there is nothing to set beside it. Christianity and international Socialism are as weak as straw in comparison with it. Hitler and Mussolini rose to power in their own countries very largely because they could grasp this fact and their opponents could not.'
https://www.orwellfoundation.com/th...the-unicorn-socialism-and-the-english-genius/) But he saw no such insight in Mosely and IMO he was right.