I've always found it easier to just use two gliders with a single central, usually finless, carrier tube. This also allows you to add length as needed, so you end up using less nose weight if needed. That 1467 internal pod orbiter sucked even when it flew 'right', as it weighed around 8z, most of this being the pod needed ballast weights. All that, on even a C5-3 was pretty dismal by my standards.

I've tossed around the idea of making a rather large full stack, but the diameter of the ET gets pretty out of sorts considering the size of the orbiters I'm considering. IIRC, that UHS shuttle project back twenty years ago in Sprocketry did not need fins at all due to its size, which was 1/40 scale.

Of course, it would be lots easier to just do two orbiters of good size and place them on like a 3" or 4" tube setup, but that would be cheesy, as orbiters rightfully 'belong' on a stack.