I Tested ground attack.
I had 2 points into it so it did 27-30% of 2h damage (I used a 2h axe, with 41 tactics and lvl 28 axe [I think])
My 2 handed axe did about 621-704 ~ damage.
According to my math 27-30% would yield a damage of 167-190 @ 27% and 186-211@ 30% of splash damage.
I tested this math in the game and I was averaging about 180-190 with some few high hits of 200. By my own numbers it seems
ground attack wasn't buffed in this patch damage wise.