FWIW: I have over 250 artillery strikes used to my credit (What can I say, I'm a sucker for damage falling from the sky). Interestingly my win rate is about 20% higher with artillery, and 20% higher still (45%) if I use artillery accuracy.
Let's be clear there have been a lot of upgrades to get Arty/Airstrikes to the point they are now:
1) They started at 5 damage per shell with a like 5m radius.
2) They upgraded it to 10 damage, 10 m radius.
3) They upgraded to 40 dmg, same 10m radius.
At this point I'm getting quite proficient at nailing 80-120 damage strikes with artillery. Best kill so far was a boars head who walked through at least three in a fit of bad luck. I guess it was an XL kill.
How damage is applied:
Damage rains down in various 'shells'. Each shell does 40 damage at point of impact with diminishing radius damage outwards. The point of impact can either be on a mech itself (ideal) which causes damage across about 50% of the mech or it will be on the floor itself, which generally tends to only injure the legs and or limbs.
In my experience:
Artillery is good for area denial but less than optimal for killing/wounding an enemy. It's great for clusters of enemies (I frequently see 2-3 component destructions from groups of 3+).
Airstrikes are harder to hit larger groups with but are far more devastating to single opponents. This is because they rain down their strikes in a very narrow strip, which allows for considerable overlap onto the enemy mech(s).
Positioning:
Artillery
Took me a bit of playing/testing to figure this out. But there are several caveats about positioning. First is that an artillery strike blobs out in a square over your target marker. However, this is not a uniform square. It generally tends to be mostly FORWARD (closer to you) of the marker smoke. This works in your favor but your first few strikes may end up hitting nothing if you simply target directly at your enemy.
Try to target about 25m PAST the lead enemy element. This will typically result in at least TWO landing directly on him or very close. It also has a secondary plus of them not seeing the smoke since it will generally be behind them, resulting in them being blind to it.
Hitting a specific range with your smoke can be difficult, so I find the best trick is to aim for something like a rock or building that's near them, that way I can be sure of the distance. Launching it from above (i.e. you are higher than them) makes it easier as well. Otherwise I might be off slightly (especially if we're on level footing) by 50-80m or more, in more egregious cases, and miss utterly.
This is especially true when you're trying to block a capture. Artillery is especially useful for stopping 'base rushers'. Simply aim the artillery at the central tower on the base cap point and it will rain hell on everyone in the square. They usually scatter when the shells start dropping.
Airstrikes
Airstrikes are far more 'point and click' than artillery. The strike legitimately begins where the smoke drops and ends in a straight line (25m wide w/out accuracy) further away from your launch point. It tends to land shells closer and thus there is considerably more overlap resulting in (by my estimation) about 50-75% MORE radius damage being dealt to an individual mech. It's good for hitting poptarts (aim on side of hill they can't see, the strikes will land on them if you're accurate enough) or wiping out an individual mech from the back (aim at their foot).
Enjoy
3
