If Dr.J rolls 100k into a db plan;can he have investment autonomy over the rollover;while the pooled DB money is managed separately?
If the segregated monies grow tenfold does it effect the valuation in any way?

The rollover monies can be participant directed. The plan document should spell this out. They will not affect the valuation whatsoever.

Assuming this isn't old DB money, it won't affect the valuation.

what if it is old db monies

If it's old DB money, you've got Code Section 415 issues, as the old and the new combined can't exceed the limitations. Since the old money was paid in the past and the new money hasn't been paid yet, you've got multiple annuity starting dates. There are several schools of thought on how to do the calculations, but all agree it's a mess.

To be clear, the rollover dollars, whether old DB money or not, will not affect the valuation. If there was a previous distribution from a DB plan sponsored by the same employer or related employer, that may affect the DB valuation.

... assuming the old plan and the new plan (or rather, the sponsors) have something to do with each other.

the old plan was 2 db plans for same company.
they are both being terminated and a cash balance is being installed.
Client may want "added protection" of Erisa plan from creditors than roll it into IRA.

does asset growth of the segregated old db monies affect val in any way?

This answers your question.

Still unclear;didnt you say if it was from a terminated plan that was same plan sponsor it could change val?

No, you are confusing two points. A distribution from a DB plan sponsored by a related employer affects the 415 limits. If someone has a lesser benefit in the second plan because their 415 limit is reduced due to the distribution from the first plan, that affects the valuation. It's that amount of the distribution that has the effect. The changes in value once it moves to an IRA, a DC plan, or another DB plan of the employer are totally irrelevant. That is why I made this statement:

To be clear, the rollover dollars, whether old DB money or not, will not affect the valuation. If there was a previous distribution from a DB plan sponsored by the same employer or related employer, that may affect the DB valuation.

So once again, it's the distribution amount that matters, not the rollover amount. The rollover amount can change all it wants and it makes no difference. It's the distribution amount that is considered. Does that help at all?