Exactly. And from what I understand, they stay that level that they were and eventually start getting pwned by everything. So it must matter which Followers to use depending on your level. And btw, does "when you meet them" mean when you first speak with them ever, or when you first take them on or hire them?
pretty sure it's when you first enter the zone that they're in, you don't even have to look at them, kinda screwed up if you ask me. If you're on PC I believe if you open the console, click on the person, type "disable" (without quotations), then enter, and then click again and do "enable" it should reset them to your current level, keeping inventory intact. haven't tested it myself though so you might want to save your game first.