I have no idea how the track compares between my GU and swan, but I have no issues towing it on sand, and the GU sure as hell isn't a powerhouse. I always air down the patrol tyres, but never have dropped pressure in the swan.
Not saying there's no way towing on sand could be an issue, just that if a GU can do it pretty much anything has a chance!
Anyway, speaking of swans, I gotta go load mine up. Mum's here hanging out with the kids and me and the main squeeze are off for a kid free camp until Sunday in a place where mobile phones don't even sometimes work!