Your 71 idea also doesn’t consider that one hole might be a double.
And if you take 127 other players and line up their distributions (their bell curve performances) it still favors match play being easier.
Match play has “more luck” but you can also play poorly and run because your opponent has a bad day. Heck you could shoot 78 and win. While that would knock you out at stroke play. Ultimately the luck evens out.
Look at tennis. Top seeds often make it through.
Or bowling tournaments.
So far I'm the only who voted that 128 person match play field would be just as difficult to win as a 128 person stroke play field. For the sake for this discussion, I am using the "average" PGA tour pro or "average" player relative to the field. For the average players, I think both are equally difficult (statistically speaking) but I also believe the answers change at the extremes.
For the elite players, I think it's actually much tougher to win a match play event. For the lower end players, it is probably much easier.
Consider the fact that during a 4 round stroke play event, an elite PGA tour pro's scores will probably look something like this - 66/63/71/68. Solid stuff and likely to lead to a top 5 finish if not an outright win. But on that 3 round where the elite pro puts up a mediocre 71? He probably has a better than 50% chance of getting knocked out.
Meanwhile the odds on going against just one person probably favors the lower end players quite a bit more. In words, a 100 ranked tour player who is probably - on average - 1 shot worse per round than a top 10 pro, has a much better chance of overcoming his 1 shot or less differential on any given day than he does on a cumulative basis over 4 days.
To the second question - In a field of 64 vs. 144, it's hard to see any argument for larger field being easier, even when considering the variance on a day to day basis.
I did. 10 GIR on both days. Were it not for a couple blowup holes (two triples in addition the aforementioned closing double), I would have won easily. I need to find a way to get rid of the big numbers….