No, that's an acceptable level of nerditry that doesn't cross the Line. They're engaging in physical activity, probably learning a little about history, and so forth. If they're actually really making metal armor using old techniques, then they're definitely learning a skill, even if it's a historical and no longer practically useful skill. But even the guys just putting on plastic armor and genuinely sparring with PVC-duct-tape-and-foam weapons are at least engaging in a light-hearted martial art.
Nice so I'm a cool nerd

we don't do it the way they did back when, but we still make our own armors and weapons

still hurts when you get struck

Outside of Skyrim, I do think Kinect is a good idea for kids It's quite the workout and improves motor skills and encourages team work and healthy competition.