imho it is pretty necesarry to have the string touching your nose at least "somewhere" for most people. Typicall it is the tip, but i have seen good shooters/pros who anchor differently. Here is Brandon Reyes (Mathews/Tru-Ball). He has an odd anchor imo, but it works for him obviously. The thing is, most of us arent nearly as consistant as these guys, so it is alot easier to keep it simple, and use the tip of the nose/corner of the mouth style, whichmost do.

If you lengthen your DL by 1/2", straighten your arm out more, you should be able to keep your anchor pretty close to the same as you are comfortable with.
I shoot with a pretty straight arm, and a hair longer DL and i seem to be able to hold better, and my releases seem cleaner b/c of the joint alignment. My stance in this pic is a little tooopen, but you get the idea.