Slitherine

I see bows against heavily armoured foot receive a -- POAs, it means they shoot hitting at 6.
If such as heavily armoured foot is also behind fortification then should be a further -, it means would be ---.
Do we shoot anyway hitting at 6, or in this case we don't shoot at all?

I think that like in impact or melee combat, for shooting -2 POA is as bad as it gets - no additional penalty beyond this.

as was said above you cant get worse than a --, so a die roll of 6 is needed regardless of how many -'s you might end up with