The size of your territory does not necessarily correlate to your opportunity for success. Time is your most precious resource, and the time you spend on lower tier accounts in your territory take away from time you could be spending pulling more revenue out of bigger ops. Let it play out, see how it goes.
Depends...did you have a good year just prior? Or a bad one? If it is the former, assuming the number still seems achievable, take it as high praise and confidence from your superiors and get back to the grind. Consider re focusing your efforts if needed. If it is the latter, might be time to pull the chute and see what else you can find...quickly, because it sounds like your company is doing it now.