... Does this really count as Huge Breasts? I mean, they technically meet the guidelines provided for it... but they're actually just rather large breasts on a girl with a tiny head.

I added the "small_head" tag to see if there was any precedence. Guess not!

You missed the tiny head precedent. It's better to run a tag search on partial phrases or even partial words to see all the variations that arise.

Wisdom +1!