The specs will definitely help once you're hitting 4 times a day. Also, imagine the possibility of surpressing two deep chain targets with one province only. If I am at 400 acres, and they've got two provinces chained to 250 acres, I can keep them both in check. I can make up to 16 attacks a day anyways, I'll get enough land, specs and pessies to keep up, and won't grow to fast due to them giving low acres. Besides that, you won't be a T/M target at 400 acres. :)
Av/Tact is just going to have to sit at the bottom of the province grinder of a kingdom, and finish it off completely.