You a right in mostly what you think. the hob needs to go to the cooker point, as it takes the most power, and the oven and be plugged in. (Be aware, if the oven has come with a plug top, if you cut it off, it may void the warranty.)
I usually try and put a double socket for the oven to plug in to, usually they'll be one somewhere e.g. for your washing machine.
But, if you take a socket off/or wire the oven with the hob into the cooker point, then you are not protecting the cable that supplies the oven.