I consider Frog Toggs as a consumable/"wear" item (sorry); I would rather have them along and not need them; however, if they wear out, no biggie. They do what they are supposed to do, but they surely ain't a lifetime investment.
My FT jacket is sized so it fits over my Joe Rocket Santa Fe mesh hot-weather riding jacket. If it is cooler and I am wearing my First Gear Kilimanjaro jacket then I don't need to wear the FT jacket.