I guess he meant to say that each product has its own attack surface, using n different products just make your attacking surfaces multiply by n. It would be tr

I guess he meant to say that each product has its own attack surface, using n different products just make your attacking surfaces multiply by n. It would be true if you mix those at the same layer. Even if you deploy them in different layers, you still have n different types of devices to maintain instead of one. And it would provide little benefit if different lays of the network were not segregated correctly as the chance to breach the very first layer remains the same. Plus the points you pointed out, there is not much point to deploy such strategy unless you have more than enough budget.