Is a loaded tipper going to get blown over? No. It it higher than a van? Yes.
Is a car transporter at 16 foot going to get blown over? I wouldn’t have thought so with all the gaps the wind has to go through. Is it higher than a van? Yes.
Is a tanker going to get blown over? No. Is it higher than a van? Yes.
Is an empty Luton van going to get blown over? Quite possible. Is it higher than a van? Oh wait it is a van.
Just say high sided vehicles is a bit vague and needs clarifying.