"I see far fewer pros in America competing in that than the American divisions so there is much less competition"
In international style there is a pretty sharp divide between the graduates of intense overseas youth programs (or those from the first comparable US programs who are just starting to turn pro), and with very few exceptions almost anyone else.
American style might have more competitors standing between an inexperienced professional and a title, but they are going to have a much more variation in strength and experience, so progress in climbing through the ranks is likely to be more apparent.
Despite this, it's probably wiser to pick a style based on what has personal appeal. Investing a decade or more of life in something isn't worth doing unless it's going to be personally rewarding.
Had a look at results from last year's Ohio Star Ball. In the open professional category entry sizes are quite comparable between International and American style. In the rising star, smooth is moderately larger than standard, and rhythm much, much larger than latin.