Don’t fall for the marketing hype of a life insurance company being great because their ratings are “Superior”. In the grand scheme of things, this really isn’t the most important aspect of what you should consider when purchasing of a life insurance contract. Not that it should be completely discounted, but I wouldn't make it a consideration of the highest order, maybe second or third.
Realistically you should be much more concerned with the actual performance of an individual policy from the company vs. the platitudes about financial strength and stability that a company touts in their marketing material. Because here's the truth, almost all of these companies (not all though so watch out) have stellar balance sheets–that sort of comes with the territory.