Piper Classique,
I'll try to elaborate a bit. Two mags are there to (1) provide a full burn, (2) to produce some power if one fails "redundancy", (3) they work indepently of any power supply/generator/battery, (4)they "should" both work together & I was under the impression that they were, I may have been wrong there. If there was a serious mag malfunction then yes that would upset the thing, however the rain shower, in my limited experience of flying but long experience of driving/riding circa 1957, I consider more likely to produce carb ice than a flooded ignition system. My only experience of a swamped ignition was in a MK 8 Jaguar that blew the radiator & soaked everything. Within a few minutes things had evaporated/dried enough to restart. Coil/distributor system of course.
I may be wrong again but I believe that the magneto does not produce such a good spark as the coil system? Stuffing a wet rag into the plughole on a motorcycle magneto & kicking it over gave me a belt!! but not as serious as the latest, prob non survivable, electronic stuff. Which is why it was discontinued in cars.