Fielding attributes continue developing long after the other hitting/pitching coaching attributes stop.
The very first team I ever inherited had 3 owners in 3 seasons beforehand, all 3 had 50 fielding IQ guys. My first season i acquired a 90+ IQ FI and all my SS/CF/3B/2B developed at maximum speed with +1s and +2s, even the guys with 3-4 pro years, it was like they were making up for lost time.
Thus, @hockey I have no problem developing a future mid-90s IQ with 100 loyalty, guys will get the points eventually on the back end.