The best conclusion from an analysis of the LEVEL of RIVALRY in the Supermarket and Grocery industry is that the Rivalry is

Strong$/$High because switching costs are low, there are new unique entrants, and the industry has a slow growth rate

Strong$/$High because there is so much product differentiation among the companies and they all sell very different product lines.

Weak$/$Low because there are different strategic groups and the regional and national chains don't directly compete

Weak$/$Low because with the slow growth of the grocery business, each firm has a clear marketshare, thus reducing rivalry.