Inspired by the Theon question, if The North American was only able to bring half its strength south with Robb, why then was Theon and the other Iron Born commanders able to make so much inpact against fortified strongholds, which the Iron Born should be numerically and tactically disadvantaged against?

Discussed in my analysis of ACOK. Short version is that the North didn’t mobilize ahead of the invasion and then got distracted and divided by the Hornwood Crisis. 

And then the scriptwriters for Westerosi Wrestlemania CCXCIX got a little bit crazy, so Theon fluked the capture of Winterfell and Reek hit Rodrik Cassel’s whole army upside the head with a folding chair while the ref wasn’t looking…