I´m trying to come up with a different solution for hidden units for solo-play than the version suggested in the updated rules.
I´m thinking more along the lines of "complete-information" so I can utilize the rules for hidden movement and hiding units during play. I guess you could say I´m looking for a more chess-like solitaire that sacrifices the "fog of war" element.
So, the question becomes how the hidden units are made "safer" than normal units. Tide of Iron makes concealed units invulnerable to fire until they are revealed. I guess that idea could work although hidden units might feel unrealistically safe. Another idea would be to allow unassisted firing (no CAP or card addition to firepower and no group-fire) at hidden units. This might prove more in line with the normal two-player experience where people sometimes shoot at suspicious hiding places but might be hesitant to spend caps to augment the firepower since they don´t really know if they are wasting their firepower.