I am pretty much mirroring what KC and lbarber said.
I don't see a need for hack squats. There are so many ways to back squat and front squat you can vary it up.
I agree that having at least a couple different routines lifts wise. Not only can it be more beneficial but I can assure you, that doing the same 8 lifts 3 times a week will get boring fast. No matter how well you progress.
I'd like to see a fair bit of unilateral work as well. Baseball players can become terribly imbalanced because we go from one direction all the time. Not only does this predispose you to injury but it limits performance as the body wants to be balanced.
Lunges, Split Squats, Step ups, and there million variations are the primary lower body unilateral movements. Single leg romanian deadlifts too!
1 arm presses (horizontal and vertical), 1 arm rows would be upperbody, if your beastly and can do 1 arm pullups than more power to you, but very few can haha. I know there's tons of options I have just blanked out for the moment.
Here's a few baseball intended 3 day splits. At the very least some food for thought when you look at designing your own program.
It's not so much the exercise selection that I feel is worth looking at. It's the thought process and incites they provide.
Jason Ferrugia's program
Grant Neary's adapted Westside for Baseball