What Niwashi said. Also, I'm unsure what you're trying to accomplish regarding retainer equipment exactly, but defensive stats are completely meaningless to a retainer. For DoW/DoM retainers the only stat that matters at all is item level. It doesn't have to be sensible gear or anything like that. Completely wrong stats for their class will be just as effective as gearing them 'properly'. For gathering retainers they're a bit more logical in that the gathering stat is the only thing that matters.