Also you might consider removing/modifying some growth related traits and/or ancillaries. Like an overseer is something that is pretty much included in farming upgrades and doesn't really need to be part of governers' retinue. Since the minimum bonus that any trait/ancillary/building can give is 0.5% (which if you think about it is huge, considering it is for a season), some of the smaller bonuses could be scrapped. Just a suggestion if all else fails.

On this note, Sardinia and Corsica are huge by 234bc. Almost gave me a heart attack when I seized them with my not so masculine forces.