CSE seems to be a NY thing. I (and Google) didn't see this associated with any other state. I'm not familiar with what the position entails.
To answer your question. If I was looking to evaluate a student and knowing that IDEA is looking for students to be assessed in all areas of suspected disability, I'd look at the school records & put on my detective hat. If I saw low math grades, I'd suspect a math disability. If I saw many referrals for behavior, I'd suspect a behavior disability. This would be the guide to use for whomever was coming up with the disabilities I'd suspect in a student and the direction for a triennial evaluation to head in.
I'm not sure if this is normal or not but it is not a conflict of interest to review records in order to plan what's needed to go forward. Also, in very small school districts you'll find that one admin will wear many hats.