Mentally challenged Hall of Fame (baseball) pitcher - can it happen again?

Rube Waddell, in the early 1900s, pitched like Randy Johnson but had the mind of a child in numerous things; coudln’t keep his own money, would wander off doing things like chansing fire engines, etc.

I am beginning a novel about a Rube-Waddell type player. It would be great if you could coment and start a general discussion ont he following:

A. How would such a hurler develop mentally as far going from being a “thrower” to a pitcher? He has an older brother who cares for him, so I’m guessing the brother has read all the books on proper pitching and how greats like Tom Seaaver, etc. did it with very few injuries over the years. And, he likely has too. Is this enough, that he pitches like he does because “That’s how the book says to”? I figure he’s been in the Special Olympics, but otherwise just pitches out in the backyard, fantasizing about being in the World Series. So, he’s developed the arm strength, as he’s been dong it from 60’6" and has a Randy Johnson type repertoire (he’s about 22, I could advance him a year or two if you think that best, though)

B. Is it logical that in all the pitching to a homemade backstop and running after the ball that he not only has the arm strength, but the stamina that kids coming up did 50 years ago, back when they played from morning to night? After all, nowadays pitch counts are about 100, but back then, pitchers were throwing 150-175 pitches regularly and not tiring.

C. Would it be logical, though most sports have all their players rooming together, for this player to need a roommte? Woudl you say another player is good - I have a plotline I’d like to follow where this catcher, who really thinks the pitcher is just weird, gradually gets to be really close friends with him. Even though the pitcher does weird things like bring a cow into the clubhouse so the team can have fresh milk.

D. Speaking of the above scene with the cow, I have a few ideas for this hurler’s thought patterns, but want to make sure - would his speech and thoughts be exactly like the average 7-9 year old? Or would he have a more developed vocabulary, just because he’s had so much mroe time to build it? His reasoning would be much more simple, obbviously. And, he’d still be able to know a lot about baseball rules, as even some kids that age that I know. But, how limited could his capacity be for him to be a “pitcher,” one who is really advanced out there, and not just a “thrower,” one who just blows it by you. (Of course, that could be solved by the catcher becoming his “personal catcher,” as numerous hurlers have had. But, could he even develop into a pitcher?)

I am figuring him at a 280-inning pitcher, and I have heard that pitchers who pitch that much before age 25 usually have too many arm problems later, but as you approach 25 and beyond the problems are less & you can go on to pitch 280 innings regularly. (Not that anyone does anymore :frowning: )
The manager can still have him go every 4th day eventually, going 123415231452… at far as the top 5 starters. Or else, he just has 35 starts or so, goes 9 pretty often, and maybe even gets a relief appearence or two in to get up to 300 innings. (He wont’ have a slider, which I hear is dmaging to the arm; what about a forkball or something?)