No he’s his examples he’s talking 50 stores over 10 machines vs 50 stores over 5 machines. Both would require the same DB count, but the second would save on server costs for stores.
Having 1000 connections doing 1 request per second isn't the same as having 1 connection doing 1000 requests per second.
But, and I could be wrong, the larger factor is the number of requests per second.