I would add, the type of person who wants a prescriptive hierarchy of relationships. Not sure if you lump that into growing a family. I don't, because it seems a lot of those people keep everything segregated in predefined boxes.
I would say, there is definitely a clash when these different types try to intermingle. They view life differently, want different things from their relationships, and these different things are not really compatible
But isn't it the same story with dating in general, not just poly? I mean, some people date by letting relationships grow organically, other people are looking for a wife/husband, white picket fence, and 2.3 children, and still other are just looking to screw around without forming any romantic attachments.
Gralson: my husband (works out of town).
Auto: my girlfriend (lives with her husband Zoffee).
The most dangerous phrase in the English language is "we've always done it this way."