I am looking to dive into the MB ecosystem after a few years of Fate, 3.5 clones, BitD and a few minor systems. I cannot wrap my head around how to approach this: should I get Mörk Borg base game before trying other material, even if it is marked as standalone but compatible MB? I am thinking about Pirate Borg and Solo Borg. Would it be better from mechanical point of view to get a good knowledge of MB first?
(There’s also an obvious reason to get base MB which is art. I am obviously getting it at some point but I wonder whether I should get it first.)
If it is a standalone (and most x Borg type things are) there is no need to get Mörk Borg itself. It isn’t like it is a core rulebook that others need to build off of. If anything I would say that this family of games is the opposite to that. The books are so much about communicating the vibe of that particular game and the underlying rules are very simple. I’d even say you don’t need to use the game a particular supplement or module is explicitly ‘for’.
You might get some clashing aesthetics but that isn’t exactly out of place here. Buy the one(s) that looks cool to you, hack at them how you like.
You’ve played Blades, and FitD/PbtA is probably the closest to the Borg ecosystem out of the games you mentioned. There is no one ‘core rule book’ just different games founded on the same principles.