Steve
Rest assured, I always read the small print! ....and I have never had a new car (in recent years) that comes with less than full breakdown cover - although as I explained this varies tremendously according to the car, and you obviously have to read the policy details. There may be cars out there that only come with the limited cover you mention - but I haven't come across any.
As you say, if you have an accident you may not be covered by your breakdown cover, but that is because it is then an insurance matter, and it is important to have a decent car insurance policy. Similarly your caravan will be covered for accident including recovery after an accident if you have a decent caravan policy, and a decent car breakdown policy will cover your caravan also for breakdown. Personal illness or accident is covered by a decent personal travel policy.
The operative word in all this is "decent", and you obviously need to read the policies in detail.
If you feel safer with the Caravan Club, that is fine, and your choice, but we are all free to choose the cover we like.
I think Nigel's question was merely about acceptance of 'vans over 7 metres.
Keith