Support ships showing up at all in the B5 universe can be kind of odd, especially since ships that size generally can't open their own jump points and inflight rearmament was never depicted in the series.
I'm not sure how many species are in TBP right now, but I'm guessing we would need sound files for every one of them. That's 3 x Y = # of lines needed, where Y is the number of species. The Shadows could use that weird electronic chittering noise they've been known to make. In the end, if we don't want to reuse lines for different species, we would need to record for more than the default 3 messages. Kind of depends on how thorough you want to be.