Which has priority – a Will or an insurance company?

The proceeds of life insurance policies pass according to the beneficiary instructions with the insurance company.  These proceeds are paid outside the estate, and the will has nothing to do with it (unless the beneficiary does not exist).

This is often misunderstood.  Placing other people on the title to stocks, investment accounts, bank accounts and other assets makes them a co-owner of those accounts.  They can do as they please with them, and they own them when the original owner passes away - no matter what the will says.  Naming individuals as beneficiaries of insurance, retirement, stocks, investments, bank accounts, etc., means those assets will pass to the beneficiary outside the estate and no matter what the will says.

There are some very good ways set up assets so that life runs smoothly, assets are protected, seniors and others receive help to manage daily needs, and everything passes smoothly and efficiently at death.  I call my practice "life planning" because it considers and includes all of this.  Whether they call it "life planning" or not, estate planning and Elder Law attorneys are very good at creating these plans.   It is well worth consulting such an attorney to avoid the situation described in this question.