Yes - these cain's can be confusing. In my tree I'm supposed to have a cain family that is realted to The famous Writer Hall Caine (but then I'm told most Cains from the IOM say they have a link to this famous man).

My Cain's have a mystery concerning a Robert cain too. Well - was he a Steele and kinley or a Cain? His mother was Christian/a (nee Kinley) Her first husband was a Steele, he died, she had Robert before she had remarried her second husband was Thomas Cain.

Christiana had one known child to her first husband, and he is my husbands ancestor. I have found 3 Cain half siblings plus Robert since. Our Robert was born 1834 - Robert Kinley or Steele, Mother Christiana Kinley or Steele, Father Thomas Cain (LDS).
Christiana didn't marry Thomas Cain till 1839.

It's hard to be sure which surname our Robert went by.

You might still be able to find my previous posts about these people.