Since you do sparring and bag work, perhaps you would know of a wrist-wearable device containing a force transducer. It would at least provide a starting point to determine force due to acceleration for a typical punch. If you did, it would be possible to equate that to the force due to acceleration resulting from dropping the Watch onto a solid surface such as a wooden table.
I can't find any meaningful data on that subject, but it seems to me that dropping a Watch even a few centimeters onto a night stand would subject it to a greater force than you would hitting a bag with it strapped to your wrist. The Watch can move quite a bit while strapped to your arm, even if it were bound by tape and a glove, which means it won't decelerate nearly as fast as dropping it from a height so small no one would think twice about it.
The Watch has no shock resistance rating, no surprise since the only ISO standard that I know of only applies to mechanical watches. Casio's "G-Shock" series alleges survival from a 10m drop onto a "hard surface". If Casio advertises that force in engineering units I can't find it. I seriously doubt any Watch would survive a similar test without exterior damage though, and wrapping a Watch in protective material to preclude exterior damage would render any comparison invalid.
If you can tell me you hit a bag with x number of g as measured by some wrist-worn device, then I might be able to equate that to the force resulting from dropping a Watch from a height of y cm onto a tabletop. However, there will still be several unknown variables requiring reasonable assumptions to be made.