Not sure how you 'beg to differ' with accurate, factual information, and your hypothetical siutation bears no discussion because we are discussing what actually happened, not what could happen. Regarding your comment about Mancunians watching City one week and United the next, that's doubtful. United have pulled in more supporters than City since 1946, so even if some were watching both, far more were watching just United
As for your playground argument comment, if you say so. I haven't said anything that would warrant that, but OK.
I had no idea about the attendances and still have unless I look at Wikipedia or something. And attendances are not the point really either. Just that for a period in my life, in my mind, City were a bigger club than Utd. This was highlighted both by their profile at the time which I suppose meant the honours won, the star players, media coverage and matches shown on TV. Albeit highlights on a Saturday night.
The same as Leeds were bigger club at the time than both of them, City were bigger than Utd. And by bigger I mean higher profile and more successful.
That's the way I see it, and your comment of..
And yet through all that they were always bigger than City.
...was not true at the time as I recall it. Sorry, but that's how it is and I'm sure anyone with knowledge and memories of the time might agree with me.