Agricultural and sewage ships become irreplaceable infrastructure

Battlestar Galactica gives the fleet agricultural, livestock, botanical, and sewage-recycling vessels, but their scarcity creates single points of failure. Sending the sewage ship Demetrius on a separate mission is especially hazardous because other ships may lack comparable processing capacity. A refugee fleet should protect such vessels like major warships and avoid risking them on work that another craft could perform. An unglamorous auxiliary can be strategically irreplaceable when the fleet has no shore infrastructure.