All of your points are sensible and wise. Like I said, this seemed like a cool theory, but personally I'm not qualified to guarantee it's true or false, and definitely not qualified to explain it as well as the poster did. I like it, but I also like other well thought out theories I don't believe to be true. I agree that all his sons being married directly contradicts the theory I was referring to. I would say Robin in particular opens up the Vale revenue streams though, so that desire could work for the lack of resources theory or contradict it. That's one mouth that pays for itself. Also you're right in that squiring out happens regularly and that great house alliances are generally cemented by marriage. We meet a lot of Frey squires and a lot of Frey brides compared to most houses, but I suppose I've been overlooking the simpler explanation for this which is there's a lot of Freys.
I tried to find the post I was referring to or a version of the same theory and couldn't last night after posting. That maybe implies it ultimately was discredited. I did find a lot of stuff that made the opposite point. I'd underestimated the size of the Frey lands, which implies I've underestimated the amount of food the Freys could have stored for winter.
Thanks for the reply.