Presidential candidates are selected through a primary process. The GOP establishment did everything it could to block Trump's ascension in 2015-16, but they simply couldn't overcome his overwhelming support among grassroots voters in the primaries.
There is no primary for the VP candidate. I'd be hard-pressed to think of a single Republican VP candidate in my lifetime who ever would have been selected in a primary/caucus process. Jack Kemp in 1996 might come the closest, but most of the others were uninspiring, dull losers whose only asset was their support among party leaders.
“The GOP establishment did everything it could to block Trump’s ascension in 2015-16, but they simply couldn’t overcome his overwhelming support among grassroots voters in the primaries.”
You contradict your own argument — that the GOP leadership will force Trump to choose a vp of their liking.