The connector body of the MIL-DTL-38999 shell and the outer conductors of the coaxial cable assmblies are using one common ground.
The connector body of the MIL-DTL-38999 shell and the outer conductors of the coaxial cable assmblies are insulated from each other.
Guiding the coaxial lines in metal armor or net mesh will protect the coaxial signal lines from lightning or other influences.
In this case the harness is a Triax Assembly. The inserts used in the TQ- and IQ-Series are identical.