Blunty, you don't get it yet?
Obviously they are not pro people. But there can be two categories of them.
First one, people with a lot of money and they just want to buy the most expensive one (not matter how expensive, they can buy it).
Second one, they just need a guidance for the future, an achievement target to set (as they don't have yet the money).
For both categories you could say: "not matter which one is the best, you won't be able to manage it, and you will blame me".
Still, there is an excellent solution and a safe answer: Nikon 1. And that is! Job done!