I tend to go overboard upgrading settlements so the self raiding goes on until about turn 40-50. Ill try the rat ogre approach next run through, usually rush gutter runners or plagueclaws as im not a huge fan of rat ogres as cavalry substitutes i usually let them support skavenslaves as it helps both units morale.
And yea i guess its not the easiest upfront, should have phrased it as after you start the momentum, by about turn 20 im generally taking a settlement every turn and branching out all directions and never bother with allies as theyll all be dead soon anyways. For the most part until expanding public order just gets ignored too, more revolts more food, i only bother once im gonna be leaving the area alone. I also don't worry too hard on the buffs/debuffs from food, the red only looks scary. Skaven is mostly about ignoring a ton of mechanics in favor of counter intuitiveness and being tricky, if you try to manage all the mechanics you end up turn 150 with like three provinces and lords ready to turn traitor.