I think the premise, "MLB teams are least likely to draft a sidearm/submarine pitcher..." is actually wrong.
Yes, I've heard individuals here at LTP make that kind of assertion, based on what they may have heard from somebody else, or their "personal experience" or whatever. None of that makes it true.
I've personally done the exercise that I suggested in another thread...that is, I spent a rainy day last April compiling the pitching rosters for all 30 MLB teams. Then, I went to the Getty Images site and looked up all ~420 of them. Out of the total ~420 pitchers, I found usable photos of their release point for about 380. I grouped them into RHPs and LHPs and then further broke down these groups into subsets of "over-the-top", "high 3/4", "low 3/4", sidearm, and submarine. After that, the math was simple: In April, 2008, by the definitions I used, there was a total (RHP and LHP combined) of 11% sidearm pitchers in MLB. There was a total of about 7% over-the-top pitchers. There was a total of 2.5% of pitchers who gave clear evidence of using 2 distinctly different arm-slots (one of these was almost always sidearm).
Okay, so far so good. Now...if you can accept that there are approximately 10 % of MLB pitchers who throw sidearm, but the percentage of sidearmers at lower levels such as High School, College, and the Minor Leagues is much less than 10%....then, in fact, the only conclusion a reasonable person could draw is that MLB teams actually favor sidearmers, as long as they can meet the competitive standards in MLB.
There's a caveat--it is relatively easy to survey a limited group like 420 MLB pitchers and then find most of their pictures on Getty Images. What's not so easy--in fact, it's impossible...is to determine whether there are more than, less than, or the same as, 10% of sidearm pitchers in all of the lower levels. The numbers of pitchers is obviously far bigger, and the photographic data simply doesn't exist.
However, any reasonable person can ask himself "What percentage of sidearmers have I seen with my own eyes at LL, HS, or college level".
What d'ya think: More than 10%? Less than 10%? About 10%?
[My experience is "Less than 10%", and I think it is that way at least partly for the reason that lower level coaches may be somewhat more automatically prone to consider sidearm pitching as a "flaw", or harmful, or some other such baloney...]