No, no! It makes perfect sense if you read the manga.
They are from the
PAST placed there
(for some reason) in the Amazon Rain Forest
(?!!) to wait for someone specific to serve
(whom no one knew was going to exist several millennia later and on the other side of the planet) but Nehelennia
(somehow) found them and awakened them as her minions. *
gasps for air* Then Sailor Moon restores them because surprise, asteroids have senshi too.
BUT
(for reasons unexplained) had to wait until the someone they were waiting for needed them in the future.
So technically they were useless until the future when they suddenly will return
(somehow) from being obscure and inexplicably go from being one note villains to secret soldiers to our
last survivors and main POV for what is supposed to be the most pivotal moment in history...
(yet we still know next to nothing about them and have zero emotional attachment)
Sure, they seem useless now and sure; they had no time to train (as far as we're made aware)...but now they're from the FUTURE-echo-echo.
So they must be more powerful than the women who have (supposedly) trained for years by this point and have actual planets backing their powers

Of course, they can somehow take down the most powerful of Galaxia's minions when even Sailor Moon cannot. Honestly, shame on you! You just can't understand the genius of Empress Naoko-Hime-Sama (all praise be to her name).
Of course, what really happened is that Naoko had wiped out every single character we care about at this point and Cosmos needed someone to monologue to...and conveniently she remembered the quartet had gotten knocked out but not cauldroned.
The only thing close to being as convoluted and nonsensical as their plot are their hairstyles.
Good grief. As excited as I was to see the quartet as senshi for completionist’s sake as a manga fan...they are such terribly written characters and it would have been so easy to fix...
Shhh! Don't bring logic into this argument! It always muddies the waters with silly things like facts, continuity, and common sense!
(in both senses of the word).