>>534769534
way, way too overkill on the ranged units.
four weapon teams is bordering on overkill, especially if you have artillery and other ranged units to manage. try making this into two seperate armies, composed of the following:

1x lord
2x hero
2x deathglobes
2x warpfire
2x slave slingers
4x clanrat spears
3x skavenslaves
2x rat ogre
2x artillery

front line is slave infantry, midline is clanrats. globes and warpfire sit in front of clanrats and fall back once the slaves break. slave slingers serve as backline ablative armor to get in the way of flanking units and to soak ranged fire. rat ogres are defensive linebackers, there to stop break thrus.

lord is whatever, but id take a warlord so he can eventually get a brood horror to ride around on so he can form a brute pile with the rat ogres. take a packmaster hero then so they all get extra regen as well. plague priests are a good hero choice to spam summons with this lineup as well.