If you have situation
ZZZ
ZZZ
AAA
AAABBB
BBB
This seemed to come up as part of another debate. To avoid confusion I have removed it to here.
Each UG is 3 bases wide. A is exactly lined up with Z. B is missile armed and within range of enemy Z. BBB cannot shoot at ZZZ as although the left-hand base of B is within arc, it cannot meet the requirement for drawing lines without passing through friends. B has to be in line with or in front of A to enable it to shoot.
Richard