There is a point where planning becomes inefficient.

The point of planning is to avert wasted time and hassle, and promote the success around whatever you’re planning.

Can I go out on a limb and say I’m willing to bet the majority of planners are over planners though?

The excess planning beforehand wastes considerable time, if not emotional energy, and becomes inefficient before the inefficiencies they’re trying to avoid ever become an issue!
Follow me?

Plan.

But better than having plan B is cultivating a spirit of flexibility, and the ability to think and rearrange plans for the better in real time. Spend your time there.