Currently the function "BIS_fnc_ambientAnimCombat" forwards its _gear parameter to "BIS_fnc_ambientAnim", but "ambientAnimCombat" has an array of options that the mission designer is limited to and will not proceed unless an "acceptable" choice is defined.
Since all the "ambientAnimCombat" does is forward that param to "ambientAnim" there is no need to hardcode such limitations into "ambientAnimCombat", especially since "ambientAnim" already deals with "unknown gear" gracefully.
This kind of hardcoding, even tho not necessary as "ambientAnim" is done well in a manner that will not break even if an unknown string is passed in, should really be done in "ambientAnim" instead of "amibientAnimCombat".
Hardcoding this in "ambientAnimCombat" also makes for unmaintainable code, and the best example is currently that "ambientAnim" can take a "ASIS" parameter for gear which will result in the script not touching the gear, but "ambientAnimCombat" will not let you use "ASIS", even tho it's acceptable for "ambientAnim" and "ambientAnimCombat" does nothing else with it to warrant such a hardcoded restriction.
While this has been altered to include the "ASIS" parameter in one of the recent updates, the check itself in the "Combat" version is not necessary due to the reasons mentioned in the ticket.