Shires Highlander waterproof fly rug sizing

[MereChristmas]

Finan has a Highlander sweet itch rug 6’ which I have been using as a sheet under his turnout. It is a little large. I am considering buying a waterproof one for summer use but am unsure whether to get 5’ 9”.
Sometimes sizes vary in rugs from the same brand.
Has anyone used both these rugs? Are they similar sizes?
As extra info’ a Rhino Wug 6’3” fits him really well and a Rhino Plus 6’3” is a little large.
Thanks

 

[TPO]

I have the Highlander waterproof rug in 6ft6. I would say that its slightly on the roomy side but I woulsnt have thought a whole size worth of room

 

[MereChristmas]

Thanks