That's OK, many of those multiple origins will be interest to somebody, somewhere. It's free and you never know, it may turn out to be a bit of fun.
SNP's can now divide Stewarts/Stuarts into a number of subgroups, as well as English Kings there are other, less noble families. Even some yonder peasant, or errant chambermaid, as in my case.
Examples of surnames of patrilineal descendants of Stwarts are Beauclerk (Duke of St Albans), Bowlin, Campbell, Cobb, Fitzroy (Duke of Grafton), Gordon-Lennox (Duke of Richmond), Macleod-Stuart, Malloure, Mitchell, Pierce, Robertson, Scott (Duke of Buccleuch), Stewart, Stu, Stuart, Thomas, Thompson and Ward.
Everyone who tests positive for SNP S781 descends from Sir John Stewart of Bonkyll (died 22/7/1298 Battle of Falkirk). His patrilineal descendants via the Lennox line (eg James I of England) test positive for both S781 and S768. His descendants via the Appin line test S781+ and S768-. Anyone who tests positive for SNP746 and negative for S781 may be a direct line of descendant of James Stewart 5th High Steward of Scotland.
Earl Castle Steward, Thompson and Robertson have a SNP that proves that one of their Stewart ancestors were alongside William Wallace at the Battle of Bannockburn.
So, the more Stewart/Stuart trees and DNA the better!