- can an engineer build an entrenchment while in an entrenchment (for the benefit of another unit to move into)?
My quess would be no - they have to be in the "hex," so they have to leave the entrenchment. Just a guess.
- how do you resolve area attacks (eg mortar) versus a hex containing units with different cover values? eg versus two units - one unit in an entrenchment - in a building hex, so one unit would have cover 3 and the other cover 5.
As per the rules (unless I'm playing them wrong!), in an area attack the black dice only are rolled, then each unit's cover roll (red dice) is rolled separately. For example, the area attacker rolls 8 dice (suppressive attack from two mortors), scoring 3 hits.
The unit in the building then rolls 3 dice for cover; the unit in the entrenchment rolls 5 dice.
Another example of note: three units in a woods hex. The attack dice are rolled only once, but each unit rolls its 2 cover dice separately - you don't roll just once and apply to all units.