I’ll save you thinking about your questions:
“Would that have been different had he been the first one in?” Nope. Trump was the last to enter in 2016, didn’t do the 15 Dwarfs any good.
“And would it have made a difference had he been more proactive pointing out Trump’s shortcomings?” Would have made him lose by even more. Trump supporters know about all his shortcomings, thanks to the DNC, Biden’s people, and the media. They get pissed off listening to other Republicans use the talking points of the DNC, Biden’s people, and the media.
The bottom line was that the nomination was Trump’s for the taking if he wanted it, and he wanted it. Even Reagan, at his prime, would have had trouble this year against Trump.
In 2015, Trump officially declared his candidacy for President of the United States almost in the middle.
Cruz, March 23; Rand, April 7; Foam Boy, April (lucky) 13; Dr. Carson and Cardboard Fiorina, May 4; Huckabee, May 5; Santorum, May 27; Pataki, May 28; Linda Graham, June 1; Rick Perry, June 4; ¡Yeb!, June 15.
President Trump declared June 16.
Jindal, June 24; Krispy Kreme, June 30; Scott Walker, July 13; Mailman Jr Kasich, July 21; Jim Gilmore, July 30.
I know Trump’s followers are “tired” of hearing his shortcomings, but he does have them. And they can be exploited. If one is not open to those shortcomings and how someone else can do better, then that’s a pretty sad state of affairs.