To play devil's advocate. When was the last time a shooter transferred to Illinois and improved their 3pt%?
this was brought up a couple months ago and i had put together a graphic... its a little dated now (Humrichous, Jake Davis and Andrej have since increased thier percentage while Z has went down.. so 3 guys went up and one went down so this probably looks even better now, but:
summary of this imo is theres a negligible dip overall (and could be attributed to many guys moving up a level from midmajor to high major ball)