I assume you may not be in th UK ?
Or maybe you live in Scotland ?
We VERY rarely have need for snow chains in the UK so i would hazard a guess that not many people will have experience of using snow chains.
My advice would be to contact Ford directly and ask them what they recommend.
Snow chains are legal in the UK... Not that we need them TBH
There are rules though that can leave you with a nice fine from the men in blue if you are found to be using them incorrectly. (i.e. not on snow or if they start to damage the road in any way)