aLL the women that I named,DID cite Houston as an influence but they ALL prefer Carey much more.It reflected through Leona's obvious copying of Carey's style of singing or blatant declaration by Christina ,"Mummy Mummy I just found the greatest person/singer on earth" after listening to VOL.
Whitney is NOT the bigger international star.Sure,her peak was bigger than Mariah's, but Carey emerged as the star of the decade and there was a time when crap released by Carey would rocket up the charts.If Houston was the bigger star,she would've gotten the WMA alongwith Michael Jackson seeing as hoe WMA's gave awards based on popularity.

Like I said,releasing more albums = less average sales per album.Same happened with Prince,Celine Dion,Barbra streisand,etc.

Not to mention,Houston benefited a LOT from having soundtracks being labelled as her solo albums when she didn't even contribute entirely to them !

In the end, it doesn't matter.
Carey has sold 203m records in 20 years.
Houston has sold 187m records in 25 years...That's a FAR FAR cry from Madonna's 300m figure who came out at the same time.