Can the cooker hood be deemed part of the cooking appliance?

[Dave A]

We have found a situation where a built-in oven, hob and the cooker hood in a domestic kitchen are all supplied off the same isolator?

The most common arrangement is the cooker hood is supplied via a socket outlet.

The cooking appliance is rated at more than 16 A so a dedicated circuit is required.

Can the cooker hood be deemed a part of the cooking appliance and thus be supplied via the same circuit?
(Solving the problem via 6.16.3.2.3 is not a viable option in this instance).