Expedition #4

Expedition #3 taught me that in LINQ, you don’t get IEnumerable<???> sequences that evaluate to null. They will always have a value, even if they are empty due to where clauses. Seems pretty obvious, but apparently not to me when I originally wrote the code for opportunistic strike zone geometry culling. Should be fixed now. So expedition #4 will both confirm this, and try to isolate the problems with the missing iniative roll.