Oddly enough I understand term "metaphoric substrate".
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What he also actually does, is andragogics (same as pedagogics, but for adults). He provokes thinking, by using his own language, he gets further questioning because his answers are thought provoking regardless when are poorly formulated. But also he does a lot of context switching because he goes to examples which are similar, but actually quite far away from original topic.
I thought the guy narrating the video explained his "context switching" pretty well. Jordan makes some valid points, but those are the "bread" of a sandwich. The "meat" of his sandwich is an absurd point, but he's hoping you won't notice, and swallow the whole bite anyway. His absurd point in your video is that "religion is what you act out". Christianity has been doing this since the enlightenment, trying to claim that because you act like the best values expressed by Christianity, you ARE Christian and you got your values from Christianity and from their God.
I think your definition of metaphoric substrate is fine, but I think Peterson takes that definition a step further. He doesn't come out and say it, again doing that context switching, but I think he believes there is some supernatural force beneath or behind our minds that is somehow holding society together. He thinks the stories he picks, some novels and some Biblical, keep us connected to that force. I don't agree with that.