I may be wrong here but I believe he is not only in charge of who is on the FISA court, but who is assigned to each case. We already know that Contreras (bud of Stroczk) was one that approved the FISA warrant. AFAIK, we do not know who the other 3 judges were. Would be interesting to know whether Contreras was involved in any or all of the others.
Sort of like how Berman always just happens to be the judge whenever the deep staters need a ruling in their favor.
Also, refer to my post #67.
I know he assigns Federal District Judges to the FISA Court, but I doubt if he is involved in who gets what case.
If memory serves, there is a Presiding Judge (Rosemary Collyer) who would be more likely to assign cases as they come in.