Yes, assuming you have two players of equal skill then knowing their tendencies is obviously better.

You are arguing that random unsigned dudes should consistently strike out major league pitchers at a higher rate than guys with professional scouting and arms warranting tens of millions of dollars.

And they are also facing others with MLB arms and scouting. I'm confident that when given the choice between "MLB pitcher who I've scouted" vs "unsigned 21 year old dude I have no scouting" every MLB batter is taking the later every single time.