There's something strange about these propagators.

In Disk 1, Ultimecia summons two lion-alike with the intention of killing Rinoa, this was the exact moment when Squall acknowledges the fact that Rinoa is in danger.

But this time, it's the opposite. Squall saved Rinoa from the space and acknowledged that she's no longer in danger. Yet, they have faced these propagators in the Ragnarok.

How can the propagators survive in an abandoned ship? Where do they come from? How do they eat? I don't think they eat machine parts to survive. The Ragnarok looks pretty heathly.
One thing for sure is that they didn't jump in to the Ragnarok from the infested Moon. Even if they did, what would be their purpose for doing so? Destiny? Destined to kill Squall / Rinoa when they come over?

These monsters appear on screen (nothing to do with game-play), so they have to be important.