Mine were all about the same give or take a bit, looking it over it wasn't as important whereas my private loans there's a larger difference interest rate (about 3% difference between the two and unfortunately are impacted by things like a Federal increase on interest rates even though I've never missed 1 payment ever).
Looking over the payoff dates though I did pay off the only Unsubsidized loan first however that was a loan that originated during my senior year of college. I don't know (it's hard to look up documents now since the pause) if that had the most interest in terms of percentage but it was accruing while I was in college (unless I had paid during that time which I didn't) vs the 4 other subsidized ones only were when they passed the initial deferral part.
It is smart though if you've got that difference to do what you did.