This is conciously done this way and I don't think we'll be changing it. Your suggestion is essentially how it was done before, and maintaining four installers for various scenarios (BN2B, BN2T, G5, and G500) gets very complicated not only for us, but also the customer should they later want those options. I won't bore you with all the scenarios a customer could get "stuck" in with regards to all of this, but I'll leave it at the fact that this is a much cleaner solution to many problems.
That said, you bring up a good point on not being able to discern which is which, so we should probably make that more obvious in the icons.