Mateored,
I'd be reluctant to comment decisively on your "what if?" since my biggest issue with the Gallo was that -IMHO - it absolutely needed a subwoofer.
I'd estimate that - in the room that I heard 'em - the TSM provided close to a full octave in additional bass extension. That delta gave the TSM a reasonably satisfying octave to octave balance, while the Gallo came up short. That overwhelmed all other differences for me, particularly because both speakers sounded so very good in all other respects to my ear.
I never heard the Strada set up with a sub, so I can't really offer a judgement, other than to say that I would PRESUME that it would be more satisfying with a subwoofer (provided that it was a good subwoofer, well matched to the Strada, and properly set up). In the end, however, that's just a presumption.
Incidentally, the Merlin might benefit from a well set up sub, as well, it's just that it's less critical than with the Gallo. I'd guess that it would be a much closer call for me were I comparing these two with subs on line, but - again - that's just a guess.
Marty