Integrators sell cameras too.
They shouldn't. News flash: there is no money in reselling cameras anymore. An integrator trying to make money selling cameras is like my landscaper trying to make money by marking up the gasoline he burns in my yard. I have no desire to buy gasoline; I desire to keep the township off my back. (I've been busy this summer, okay?) And if he marks it up too much, I will go buy it myself and mow my own lawn, DIY, sound familiar? The fact that he can do it better, faster, and burn less gasoline is why his job is secure. How much gasoline he burns is incidental to getting the job done. Likewise the number of cameras in a design is incidental to providing coverage.
My point, and I do have one, is to answer your question:
What would inspire an integrator to layout a more efficient design with fewer cameras?
A camera is a tool, and few people buy tools just to have them; they buy tools for what tools can do. You don't want a drill, what you want are holes. Would you buy fewer drills if they could provide the same or better holes? You would. And your customer doesn't want cameras, they want coverage. If they could have more and better coverage, they would buy fewer cameras in a second.
(Conversely, automakers do the opposite, not selling cars for what they do -- take you from place to place -- and instead sell them based upon how they make you feel. Otherwise, Chevrolet would have put Mercedes and BMW out of business long ago)
Same parking lot, same price. Which would you choose? This:
Or this:
(Images courtesy of Wach1Design.com. Maybe. If I had asked.)
Which "works" better for the customer? Which makes better cognitive sense? And for the same or better pixel density (better coverage, not just more coverage), they need to be premium, higher resolution and/or longer lens cameras. But there are only four of them, as well as the associated reduction in supplies and labor. Fewer devices to fail. Lower network bandwidth. Less storage and/or longer retention. And if any analytics are being deployed, four licenses instead of six. And perhaps a less expensive server for that as well if your VMS requires one.
At the same price, which would you buy? Which design would make an integrator more money?
What would inspire an integrator to sell a more efficient design with fewer cameras? To differentiate themselves from their competitors that simply sell more cameras.
"The world is changing. The Internet is killing agents, and severe competition is diluting income for everyone. It's hard to compete. So don't. DOMINATE."
-Mitch J. Miller, Agent Domination: How to completely own your market by doing the opposite of everyone else
Disclaimer: As always, these are my personal opinions and not necessarily those of my employer.