this is from memory...and that's shakey at times so take that into account lol
lure was made famous on large charter boats that would take groups out and customers would cast out around the boat trying to catch walleye. its a great bait for counting down and catching suspended fish.
i believe the extra wire is just bite off protection, done this way for simplicity. no wire leaders needed, and not having to re-tie from bite off's from pike. i dont think is a specific requirement for this to be a fish catcher, might be better with a flouro leader in fact.
french blades give very even lift. so if you cast it, count it down to 10 ft, and steady retrieve it will tend to stay at 10 ft. this is also true on bucktail spinners.
colorado's will have more lift and thump, will need slower retrieve. Willows have less lift and more flash, will need a faster retrieve speed. so just tools to you to use.