Best stand-off weapon for...

[runequester]

I find a liberal application of mortars tend to work well, with some heavier guns to cause kills.

Its hard to find a good balance between converging the barrage (higher suppression and more chance of kills), and dispersing it over their front line (less effect individually but you can suppress a larger number of formations)

Against low quality troops, once you have multiple platoons panicking, the leaders are hard pressed to keep them in the line, and once that starts happening, you can "hit the beach" as it were