Background and configuration:
I am providing mechanical protection and neatness for a 4ga grounding electrode conductor and a 2nd 4ga auxiliary grounding conductor running from outdoors into (and through) a small weatherproof junction box mounted under my service panel (in exterior-accessible cabinet on garage outside wall).
The box has 3 1/2 inch knockouts, so I would like to use one for an exiting bare ground with intersystem bonding bridge, a 2nd for exit of GEC with Kenny clamp (and Kenny clamp entry to service panel enclosure), leaving the 3rd for entry of both grounding conductors. The GEC will be unbroken but bonded to the auxiliary grounding wire inside the box via a split bolt.
Here's the junction box:
Question
Can I run both 4ga grounding conductors into this junction box inside the same 1/2" pvc flexible liquidtite conduit? I found the following allowed fill table, presumably for current-carrying conductors: