Indeed, I use Overlord's for the armor. The armor is effective in every physical damage fight, albeit minor. 5 stamina is pretty useless if you don't come close to dying, esp. in this content with over geared tanks & healers. 1% shield block has its uses on multiple mobs as well, but that's also minor. Once again, this is a personal reference sheet for myself and guild tanks.
Threat set is maximizing Crit for Impale while balancing ~425 Defense. You can certainly play around with it, but you'll be forced to use Defense items elsewhere with a bigger offensive stat penalty. This is the best combo I found to maximize crit (18.6%) with 8% hit while maintaining ~425 Def.
If you don't try the combinations for yourself with all available items, you'll obviously think it's randomly put together.
Ps. I've added a Nightfall tab for different Nightfall situations.