In short, I'm proposing the idea of having a "mini-Indirect" Special Rule that allows certain ranged weapons to ignore allied units for line-of-sight purposes. Right now, you can ignore models in your own unit and that's it.
This would allow archers and javelineers (and others as appropriate) to stand behind a shield wall and pelt the opposition with impunity.
The main reason I can see to not add this is that OnePageRules isn't focused as much on drawn out battles, thus making the utilization of this rule more of an opportunity attack rather than a deliberate setup. And, of course, the burden of balancing a new rule.
I'm not demanding this be added by any means, I just want to drum up any discussion on it like "Would you find this useful?", "What other reasons would there be to not add this in?", etc.