Wow, thanks for the reply and explanation @BallFour. So, I followed the instructions, and in this case, pitcher ohtani was the sp3, and I edited the rosters.dat of that code line to 9 from -1. I also found the line with the DH, and edited those to -1, but unfortunately it returns a "null" in the lineup spot. So, no SP ohtani available in the lineup to select.
Please see the attached photos (1st of the line of code before altering for my records, and then the 2nd of the batting order in game that shows null where the DH should be).
Looking into the rosters through Mvpedit, the only difference I saw between brendan mckay and SP Ohtani was that mckay had a 2nd position listed as DH, so I added the 2nd position as DH for SP ohtani's profile. However that doesn't seem to make a difference as both mckay and SP Ohtani did not reflect that within the game using the game edit roster. It looks like if the primary position is a pitcher, then it won't accept a field position as a secondary.
Oh well, I'll just keep using 2 fantasy draft picks for ohtani :(