To add to that, each mesh in cascade is a drawcall, and you could achieve what you want with one or two of those meshes, and just add scale, rotation, and rotation rate to them.
Not the best example since I used a mesh I made years ago, and isnt up to snuff but: [UE4] -FightCloud- Luos's A Particle A Day For A Year! 25/356 - YouTube
now change that into a better shaped mesh like you have, and I highly doubt people can tell you only use one (or two) meshes.
that said, Id love the possibility of an array of meshes in cascade or niagara.
I should @unrealalexander this 