That system is so “not-dissimilar” that it makes me wonder where the Russian designer may have gotten the basic sequence idea.
That is -very- similar.
The Russians copied a lot but this is something where form follows function and there’s not a lot of solutions. Heinkel and Saab independently both developed ejector seats during WW2; neither knew of the other’s work until much later even though both systems were near-identical.
It’s pretty obvious that you’re going to have to clear the rotors *somehow* if you want to upwards eject the crew. Pretty much the only option for that is explosively clearing them out of the way. It’s a case of form following function. There were other countries that experimented with similar ejection system ideas, including Martin-Baker of England and Bölkow of Gemany just after WW2.
The US experimented with downwards (as in straight down, not to the side and down) ejecting seats in the AH-56 Cheyenne project that got cancelled. That’s inherently a bad idea for a chopper that’s going to routinely be below 500 feet AGL. The Russians never bothered with that stupid idea.