A couple of things. The clans were never united. There were always clans opposed to whoever was in power since it diminsihed their own power. The Lords of the Isles signed treaties with England, the Campbells allied with the English at Culloden, although some also fought for the Bonnie Prince.

Personally I believe that was both the strength and the weakness of the Scots -they were so fierce at protecting their own interests, they sometimes, perhaps often, lost sight of the bigger picture. It was always easy for the English to find allies in Scotland to join with them, whether for land, religion, or whatever.

Anyway, here's a link for rogerson.

http://share-hodgson.org/rogerson.html
Unfortunately the name is so common, being Roger's son, it may be hard to link to any given clan, or even to Scotland. But that is not important - if you think you have a link - go for it- wear the tartan you choose with pride - that's all that can be asked.