Yeah that made me raise my eyebrows a bit, in the codex they have a box that says sisters of battle rely on Imperial navy ships on long term assignment and on the same page they mention Frateris militia battleships. I mean how does that work? Volunteer battleships!
Yeah, the organizational overview in the 8th dex makes it clear that sisters are quite a force to be reckoned with- the fleet information in particular surprised me. I'd like to see the range grow to represent those things; we could have an Abbess, a Cannoness Superior, a Cannoness Preceptor and a Cannoness Commander. Why not, right?
Frateris militia are also mentioned in that organizational overview more than once, despite the decree passive.
They actually called them Frateris Templar Battleships. I assume those are the on-loan naval ships the other blurb spoke about.
If Battlefleet Gothic ever came back I'd love for a Ministorum list to be a thing