You can not answer Robjects without a combat and design system. Combat to demonstrate effectiveness of systems, design to demonstrate costs and other physical limitations.
And I appreciate this is a T5 thread, but the only other system "universally" recognized on this board is HG2, frankly. Plus, most of the original canon, fleets and portrayed doctrine were done when HG2 was active.
The problem is that people posit these ideas and "what should work" etc., but nobody, and I mean nobody, plays them out. And it's understandable. Any realistic test is going to be very involved.
If someone wants to know the BR to BB ratio, you have to come up with ships and game it out. If you want to know the BR to BB ratio broken down by TL, you have to game it out. If you want to know how many TL 13 BBs it takes to match TL 15 BBs, you HAVE TO GAME IT OUT.
And to do that, you need a system.
HG2 happens to actually suit this problem quite well, since maneuver is abstracted out. Line 'em up, shoot it out. But no one wants to take a Tigress and fire 500 missile batteries.
If you start with no combat system, then you can't answer "are BR or BB better" because you can design the system to "do what you want".
If you don't want to use HG2, then the answers to Robjects questions are "whatever you want", because there's no ACCEPTED combat system in place to answer it. So, make one that plays the flavor you like.
If you do want to use HG2, then software like mine will happily salvo 500 missile batteries against your Gazelle and tally up the carnage. And it'll do that in less than a second.
As for HG2 being beat to death, I think there's a lot of folklore surrounding it -- because I see some surprising results that don't match the paradigms presented in canon.
