Why a Rebel Subjugator-class ship becomes a liability

Would a Subjugator-class ship serve well in Rebel hands?

The panel doubts the Rebels could man it, even with droids, and expects the Empire to send major assets against it.

The immediate objection is that the Rebels could barely man a Subjugator-class vessel, even with its extensive use of droids. Possession of such a large asset would also bring a large Imperial response. Those concerns are enough for the participants to reject it as an easy addition to the Rebel fleet. The short reply does not develop a separate repair, basing, or supply plan.