I think in this case the Garibaldi/Zarg thing was the "B" story, the Neroon/Marcus thing was the "C" story and the episode's real problem was that it didn't
have an "A" story.

Of course the Zarg part was made that much worse by the truly lousy rubber suit (one of the few time's
B5's limited budget really hurt a
story by undermining it to the point of distraction) and JMS's apparent belief the early firearms were steam-powered.
Still for me, in the form of the DVD, "Grey 17" is a great episode because I simply fast-forward through everything that
doesn't involve Marcus, Delenn or Neroon. (In fact, I'm thinking of off-loading the ep to my PC and re-editing it into "'Grey 17 is Missing' is Missing".

)
Regards,
Joe