jmpTT
860
Debatable, but unreasonable...
Roger Smith might pump out 15 - 20 watches in a banger year, while Greubel Forsey is producing 200+ watches pear year. In comparison, Roger Smith's watches rely on the human hand to a greater degree.
Of course if you want to fly close to the sun of perfection, you can look at Greubel Forsey's Hand Made series. In finishing quality, these compare favourably with Roger Smith, but the annual production of the Hand Made series is 2 - 3 watches. The price is also much higher, and at some point there is a tradeoff between perfection and access to product.
If the world falls apart and we return to a society that worships its rulers as deities, one can imagine, in theory, a single watch that approaches the human limits of ability, one so perfectly hand finished and complex that it takes a team of skilled watchmakers a lifetime to make.