What can I do to narrow down the draft class so there is not 3000 players in it? Thanks in advance!

Easiest way is to download the csv/json converter from the mod forum and convert your draftclass.json to draftclass.csv and then remove whichever players you don't want and convert it back from .csv to .json and import it. We don't do anything in-game since we really don't know what folks intend to do with the draft classes. Some folks mod them, some just use as-is, some adjust ratings, some remove players, some only keep their favorites from their college runs, etc.