6-10 times? Ridley's not that huge in Brawl. Stop at 00:37 in this video:
http://www.youtube.com/watch?v=iJP8TtY3eig
Notice how Pikachu isn't standing straight up. Even with the changes of perspective, I'd say that Ridley is about the height of 3 1/2 Pikachus in this scene. Ridley could be made the height of about 1 2/3 Samus's if he were made playable. Upon further inspection, I noticed that Brawl Ridley is already about the twice the height of Samus and it stands out most at
1:51. It should be noted that Ridley almost never stands up perfectly straight either when he's on the ground. Because of his rather unusual body structure, he always has his limbs bent at an acute angle when he's stationed on the ground. Look at these pictures for example:
If he were standing up completely straight, yes, he'd be obnoxiously big but when you add his "ground position" to the theoritical sizing down, you would no longer have a character that would be completely unnatural in an SSB setting.