My friend and I got in a little discussion of what would you do if you were Robb Stark at the start of the war. I was thinking that in the book before the north even got involved Edmure and Hoster Tully were already engaged with the Lannister's. So keep the Tully's strategically falling back, fighting them but not trying to out muscle them because you can't and lead them through the Riverlands. Then I would take Theon and send him to the iron islands to retrieve his fleet and although Casterly Rock is an impregnable force, with 60k Lannister men deployed and split up led by Jaime and Tywin Casterly Rock must not be heavily protected then have the Greyjoys attack and take Casterly Rock then claim you will give them their hold back as long as we can get Sansa back and Ned (if you achieved this before he's dead)

Major fault in Theon's identity crisis but no one could've predicted that, Robb didn't so my plan would mainly revolve around Balon not destroying Theon.

Second plan is just team up with Renly, the man had 100k men! I know Robb is a Stark and honor and all that but I'm not and I could give a shit about a rightful king, as long as the king is my ally and my enemy doesn't sit the throne I'm fine with that, just as long as we can defeat my enemy