Speaking of 62Es, which base has the largest concentration of aerospace engineers (literally "aerospace engineers" defined by their college major)?

Assignments are determined mainly by AFSC, not necessarily by what flavor of engineer you are. For most assignments an engineer is an engineer, very few jobs truly require a specific breed. Without having the actual statistics, aeros will be pretty evenly dispersed.

I heard that LA and Hanscom are heavy on the EEs. I guess it doesn't matter for AEs because aero is interdisciplinary.

That is true about EEs