One way Judge Merchan could handle sentencing:

[Irish_Dem]

140. Yes of course he does: he is rich, male, white and special.

He and his attorneys can take it to appeals court and delay for some time.
He can rightly argue that it has nothing to do with sentencing.
And that it will hurt his campaign.
The SC may agree with him.

Trump can also screw around and play games with the psych testing.
The psychologist cannot make him answer the questions, take the tests, or cooperate.
Or he can give nonsense answers and play games.

The judge does not need this information to sentence Trump.
I believe the judge is making a big mistake if he goes this route.