You're right, there is obviously a larger picture to keep in mind.
Main reason I did the Omaha scenario was to practice before starting a campaign proper.
Not that it has much impact on this scenario, aside from a handful of German engineer companies that can hustle to the beaches around T5 IIRC.
There is a fresh infantry unit right next to the Colleville exit the German player can cycle if needed, and if you try to disrupt both that, and gain a foothold into Colleville itself, you have no fire-support left to try and gain another exit.
Which means a one-hex breakthrough, and that's assuming your engineers stay alive for long enough to actually breach the AT-ditch in the first place.
I do like the Alternate Fire OR though, at least for indirect fire. Personally, I think default artillery is a little weak, but that's just a gut-feeling/personal preference.
But it does discourage unrealistic stacking, and avoids the Doomstack issue.
Plus, it avoids the (IMO) gamey technique of targeting enemy AT assets, and then just run rampant with your armor.
Yes, in real-life the commanders would target enemy AT guns with artillery, but they weren't able to sit at a distance and kill them before even moving armor into range.
I guess the OR just breaks down when you have massive stacks on a 200% beach-head.
Oh well, it is what it is.
No great loss, I'll simply switch to The Bulge. ;)