I'm an identical twin. My sister is the more tom boy one, and I'm more girly. The guys seem to be more interested in her then me. Is it because guys prefer more athletic dressed girls. I mean if you saw me you would know I'm athletic. I play softball, I dirt bike, I sail, I swim, I kick box, I wrestle, I lift weights twice a week. So its not like I'm really girly. I just love dressing up. But why do you think guys find her more attractive?
Tomboys are less threatening to a guy. So guys are more inclined to approach a tomboy and joke around with her, but while they are joking around with her they may be glancing at the "girly girl". In the long run I think guys will pick a "girly girl" before a tomboy. but its more about her personality than how she dresses.
I think it may be that they see her as "one of the guys" and will have an easier time talking to her. They view it as just like having a conversation with one of their sports buddies, than trying to make an interesting conversation with a girl who appears to be more interested in shopping. I don't think it's that their more interested just feel more comfortable.
All guys are interested in different types of girls. Some guys like the more girly type, while some are interested in more athletic. It just depends on the guy. I think most guys like a little of both.