Sailor V and Card Captor Sakura were conceptualized around the same time

I don't think they would've been in competition, the two series are two completely different types of Magical Girls. Sailor V/Sailor Moon was a new revolutionary type of Mahou Shojo that combined Toukusatsu/Sentai and battling with being a Magical Girl, making it more akin to a traditional Western Superhero franchise than any previous Mahou Shojo released at that time.

Cardcaptor Sakura meanwhile was more in the vein of a traditional Mahou Shojo, where the girl just has powers that help her out in her day-to day life but she doesn't reallly "fight" with those powers. Additionally CCS in particular doesn't put a great emphasis on the actual Magical abilities like Sailor Moon does, rather that Magic is just used as a backdrop for the real focus of the series, which is the importance of relationships/bonds. (Sailor Moon has this too but to a lesser extent than CCS since it's more plot & mechanics focused)

On the contrary, rather than being in competition I've noticed that SM & CCS tends to have alot of fandom crossover and most fans of one are also fans of the other. (I know I am, they were my first 2 Mahou Shoujo series, with SM being my very 1st anime in general and CCS being my 3rd)

I tend to think that when CCS got published it grabbed the attention to SM, I actually preferred if the first draft of CCS in the 90s was the one that made it because it would have not had the controversial aspects of it like the Pedo Inneudos due to aging down the characters.

CCS was influenced by Creamy Mami even the prototypes show it.

Both the 90's anime of SM and CCS have pedo innuendos unfortunately.

It is sad that Sakura Kinomoto and the other characters of CCS got aged down in the development and Chibiusa got more attention and popularity than Usagi.

I actually preferred if the first draft of CCS in the 90s was the one that made it because it would have not had the controversial aspects of it like the Pedo Inneudos due to aging down the characters.

Without wishing to excuse more dangerous depictions of such themes, or invalidate anyone's feelings on the issue, I think there's a lot to be said for considering the context of a piece of media in cases like this. I guess it slightly dissonant to see these ideas labelled so starkly as such, as when I first watched both shows, I still had clear memories of being a 10-year-old who spent all her hours yearning after those older than me, and I considered both shows to be a reflection of that, rather than shows with strong grooming subplots.

Having said that, I would love to read that CCS prototype story, and those designs look wonderful.

That prototype story was drawn by an artist no longer part of CLAMP, Leeza Sei, and the magazine issue was way back in 1990.

Based on my Research Card Captor Sakura was already being pitched to editors prior to Sailor V's serialization with another title, had things been different it might have been in competition with Sailor Moon and minus the controversial parts since the characters of CCS were teens/adults in prototype form.

The prototype Short Story of Card Captor Sakura named Miracle You was serialized in Kobunsha's Val Pretty in 1990.