I have been experiencing what I would call “stuttering” as well. I do not know if in fact we are experiencing the same type of issue, but I would say that the game “stutters” on me, sometimes to the point of making AH3 “unplayable”.
Although I am not playing AH3 as much as I used to (and would like to), including today, I have had three different experiences were the game became “unplayable”. In each case, however, I noticed that my PC (Win 10 64 bit) was downloading an MS update in the background. I waited each time for the updates to download, (which on one occasion meant waiting over an hour), and then AH3 would seem to be fine.
I do not know if this is all just a coincidence, I am just putting my observations out there.
(BTW: I have an older PC, (8 years old?), and while I had to upgrade the video card, the PC itself is not that far off from the AH3 Recommended specs. Just a guess, but I think that this issue might be unrelated to a PCs age or spec).