No way is CV deserving more of a number than RE3. RE3 deserves it. It has Jill in it from the first game. It shows more of Raccoon City and it shows Raccoon City being destroyed. If anything, RE3 is more of a sequel to the first game than either RE2 or CV.
I hate how everyone acts like Leon and Claire are the main characters of the RE universe. It didn't start with them.