in several countries, I'm totally convinced that Position 2. is the most likely to lead to success and Position 3. is the worst possible choice with one caveat -- unless a viable operational reserve is maintained and used as stated below. Even then it offers what will appear to most observers as a very tentative and excessively cautious effort that can be an incentive to the bad guys to try harder...

In any of your positions, such a reserve is not a waste it can and should be used on economy of force and presence (read; saturation patrolling in random areas) missions throughout the region while avoiding decisive engagement to enable commitment to rapid reinforcing missions -- among other things, this can preclude excessive use of less than discriminating air power or artillery.

You will accrue higher casualty rates. You'll also enhance your chances of success in a shorter period.