The point I had in mind is that it is a matter of cooperation between cutter and tailor. They both have to do their job right, and they both can botch it up.
Any good design can be ruined by a mediocre execution, whether it’s a suit, a car, a house, a table or whatever. Similarly, any mediocre design can be improved during it’s coming into physical existence. Where is the line? It’s moving, it’s a play between two specialists, and many aspects of skill, taste and listening figure in this.

I’m very curious where you would say that the line might be drawn in the skill of a tailor for one where he has a cutter in his back pocket, versus one where the tailor falls out of his back pocket. Obviously, a truly incompetent tailor could ruin a suit designed by a good cutter, but where is the line? Could a merely decent tailor ruin a suit that was cut well? Is there anything in the reverse which is true, that a master tailor could fit a poorly cut suit?