Just finished two (3v3) games back to back where arty was used quite a bit (not by me....don't even have it in my deck).
In the first game at one point I lost a good part of one of my forward forces when I momentarily stopped moving them in order to resupply and then forgot about them for a few seconds while I was busy micro-ing another forward force elsewhere.
While it pissed me off, it was totally my fault but all it caused was me to push forward even faster. We won.
In the second game again arty was used. I lost a few units here and there......but oh boy did the micro-ing of my widely spaced units make them pay for it with high-value losses.
In the end, arty was largely inconsequential in both games. Left me with a decidedly 'meh' feeling......we won anyway!