All depends how much you want to cook!
We (4 people) usually camp for 3 nights, and have some kind of bring from home meal the first night (chilli/spag bol/fajitas) - 2 rings needed, max.
Cooked breakfast on 2 mornings (bacon rolls one day, eggy bread the other) - one ring needed.
BBQ one night - we have a camping BBQ, but also use 2 rings for things like onions/potatoes.
Pub meal or chippy the 3rd night.
Obviously we boil a kettle outside of this, but never need to use the kettle at the same time as doing any of this.
We have a big plastic crate to store pans, crockery etc in, a small 'tool box' for cutlery/utensils, and it's never caused us any issues.
So we manage just fine with 2 rings (a party grill and a basic 1 ring stove). We have a low table to put them on, works fine. Easy to pack, easy to store, easy to use, easy to deal with on site. No faff at all.
If you want to create elaborate meals or maybe if you're staying for ages then maybe the more formal 'order' a kitchen would bring might be worth it, but I like to keep things very simple when camping (and less to sort out at either end).