I also agree with Gary, four variants is overkill and more that two leads to problems also.
Hi Donald, I merely mean that four or more variants entail far more work for you, the web designer. Each image on each page on each variant requires resizing to fit the variants width. Each text style for each variant requires resizing etc, etc. It's your time it's taking up and one the client won't possibly understand nor pay for.

Mobiles and tablets, unlike desktops & laptops do a very tidy job of resizing a webpage's content to the available browser window. So for example if you create a 1200px wide website only it will display on a mobile. Display, but hardly readable without pinching/panning etc. So I prefer to create two variants, one which looks fine on a desktop/laptop of a fixed display size and a second one for smaller screen sizes which mobiles/tablets will happily shrink/grow to fill the available screen real-estate.

I've not seen a Xara variant website that has any problems displaying a site between the two variant options. However, if you and the client is happy creating/paying for more then it's not an issue

I do warn though that there have been issues reported on TG re more than two variant causing problems, which I can't confirm as I've never created more than the two.