How does this stack up to the other proposed Executioner model?
I think this one could be competitive if you chopped off the top fin, removed the side engines, gave it just the center Guardian engine, and moved the wings in/made them a bit smaller. Think F-16/F-35-style, with the small single-engine design compared to larger craft like the F-15/F-22.
Of course, you could go the Upholder replacement route with it too, since we're currently lacking one of those. In that case, I'd say put an Umibozu/Nodachi-style cannon in the nose, only canted off to the side like a certain aircraft.