Work ethic does not change based on practice minutes. It will change based on playing time and starts.
With regards to the offenses and defenses, the more practice and playing time a player receives under each set, the better the offense will function with regards to efficiency, and the same holds true on defense. If you have 5 Seniors who have been practicing your offense and defense for 4 years, you'll have a very "smart" team on the floor. Whereas if you try to switch your offense and/or defense in mid-season, many players will have to spend time learning the new system which can lead to poor shot selection, unforced turnovers, and missed assignments on defense.