If it served a purpose you would suggest some bulletin like, "all infantry with rifles gain a 3% increase in accuracy" not ridiculous numbers of bullshit.
Riflemen now spawn as doctor manhattan, a 50 foot tall supreme sentient being. riflemen in doctor manhattan form are invincible, capable of superseding time and space, and splattering their enemies via telepathic energy.
So, anyways, back on topic. I think that Artillery cover shouldn't pinpoint every unit in the area with it's exact hard counter, but instead just be random hard counters spread throughout an area.
When it hits once every 100 games, it's pretty good.
Considering it is railway artillery after all, I'd like to see it have a larger blast radius. It does say that this shell comes from the Schwerer Gustav, so I'd expect it to do more damage, even if it means a price increase.