Larnach, Martin, and Miranda started in the minors....so I'm not sure how they planned to depend on them. Farmer is clearly a backup, not someone they were counting on depending on.
My point, that you responded to, was the college players are going to be in their mid 20s before they play in the majors nearly every single time, so saying that those guys rarely work out isn't about premiering in their mid 20s, but that most minor leaguers don't work out.