TP to Erik.
I noticed it once or twice during the season as it was an early TO.
On Youtube that guy who does Celtics analysis, focuses a lot on Stevens and how he coaches from the sideline particularly on offense.
My guess is you are correct in that after 6 minutes or whatever, Stevens has a handle on the opposing game plan and starts to deconstruct it.
It is fun to watch the guys on the floor execute his calls...they know exactly what to do and probably why Stevens is making the call also. Stevens will do anything to put the opposing defense off balance. He had Al and Baynes slide to the arc pulling both Milwaukee bigs with them and Larkin throws a dart to Tatum cutting to the hoop.
Now listen, Stevens had Larkin on Simmons the other night for what seemed like about 5 or 6 minutes in the fourth (?)...and it was effective. He started Semi against the Bucks four times. Semi scored 13 points on 12 attempts in 103 minutes of play...the Celtics were 3-1 with Semi starting. The team beat the Bucks with one player getting starting minutes making three shot attempts for the entire game. Opposing coach has an extra defensive player now as Semi isn't going to shoot, but, they still can't win.
In the day, Jo Jo or KC or Cousy called a lot of the plays on the floor....Stevens is the point guard now....seems to be working out aok.