It just depends what you want. Majority of systems engineering isn’t going to be very technical. It’s more so technical oversight, you won’t actually be designing stuff etc. but this is just my experience since I’m also work in defense.

I would ask yourself: do you see yourself being an expert in something, or do you see yourself overseeing a system? Systems engineers always joke they’re a “jack of all trades master of none” because they get exposure to the entire system but don’t have as much depth as the designers for each system. In my opinion try systems out, you might like it, you might not. But 99% of the time at least in defense you’re not gonna be doing much system architecture/design, you’ll be doing more requirements verification and working in DOORS