The guy that trains you will have a lot of influence on your style, at least early on. You don't know anything or how (or what) to think about things, so you'll absorb his thoughts and ideas and your style will express them.
If you pursue the activity long enough, as you gain experience you will develope your own way of thinking and your style will change. I think that your thought process and your mentality play at least as big a role in the style you end up using as does your physicality.
If you take Patterson, for example, he fought out of the peek-a-boo style until Johannsson dropped a right hand on him. So he turned himself more sideways to see the right hand coming and changed his style