I know next to nothing about helicopters, but when I was a kid, I used to enjoy assembling aircraft models, and I recall this one weird helicopter model I built with interleaving rotors, spinning in opposite directions - the model was tricky to build because the rotors were attached to a gear assembly so that they had to spin together. The weird bit was that this arrangement meant that no tail rotor was required. I guess that configuration must have had some flaw in it though, as the idea hasn't been advanced further since then, far as I know.
That's a Kaman HH-43.. German dude named Flettner, that got spirited to the US under the same banner as Werner von Braun and others, came up with that. The reason counter-rotating designs of all kinda fell to the side is that you lose a lot of efficiency when your two rotors are busily sucking down each other's rotorwash. The two side-by-side idea is arguably less mechanically complex than the way the Russians do it But even the Russians, who did fundamentally ludicrous things with helicopters Got it down to one when they got serious about it.
You are truly a fount of knowledge, my friend. That's the one. I noticed a couple of your image links didn't embed - and those links start with "https://" - I thought that #bugski was fixed? mk ?
Aaaand now, they seem to have repaired themselves. Edited, I assume.