I don't think a change is needed. The requirement is that the enhancement has to have the person's name in the title, that is to say that the enhancement's context from the Bible was related to that person. Saul's Spear, for instance can get name-on-name bonus when used by King Saul (Old Testament) because the spear was the one he used to attack David (check the verses). However, Saul/Paul (as Saul - New Testament) can not get name-on-name bonus with Saul's Spear since they are completely out of context (and space/time continuum) and clearly not the same person.
Swift Beings has nothing to do with the character Swift. The enhancement does not have his name, it just has a word. Grammar is very relevant since the rule speaks of possessive words.