> For a small network (a home or small office network for instance) you likely have one incoming router anyway, so if that dies clock setting is the least of your worries until it comes back up, meaning setting the internal hosts by that one clock is as fine as anything else.

I'm not so much worried about the router dieing and losing sync with the outer world; but about the router's clock going wonky: I've seen computers where something got initialized wrong and they were 30 minutes slow after 10 hours (reboot helped in that case, but sometimes it's the oscillator is just too far off)