The stiffness of the joint (ability to resist rotation) is a key issue.

The lever arm is proportional to the average, or in case of grounding) load times it's "lever arm". e.g., simplistically, all things even, the resistance of a 5' deep keel less than 7'-6" keel by 50%.

The resistance of a properly sized and installed placed boat pattern is affected to large extent by slight differences from a bending standpoint. The forces involved at the traditional hull-to-keel joint in BENDING could be enhanced by the spacing of the bolts off center. Again, there are issues of strength of the bolts, contact area, etc. However, for example, if you have two rows of bolts which are 3" on either side of the centerline of the boat vs. 5" apart, difference would be proportional.

In reality, the failure of the joint is usually an issue of a combination of issues related to crushing of the fiberglass mating surface, work hardening or fatigue of the bolts, the marriage of the keel and hull surfaces, etc.

I believe that sailboats keel-hull joints fail because of mechanical damage in hitting something or improper blocking in a yard. The issues of leakage are more of cosmetic issue that should be addressed before it becomes something worse -- it's a warning that you should deal with.