What happens if witnesses as to a woman's captivity only show up after she's already married (as per the mishnah)? The Gemara explains that the mishnah doesn't mean actually married. And if she has witnesses who can corroborate that she was unscathed - that is believed. Likewise, if there are witnesses that she's NOT unscathed, she's supposed to leave her marriage (especially if she's married to a kohen). Plus, a case of events that took place - actual captive women. With Shmuel knocking his father, and with his father winning, after all. Also, a paid of witnesses who each said they were pure - they can testify on behalf of the others, but not for themselves. Plus the full range of permutations, so that all basis are covered. Including what happens if the party, or some parties, are kohanim, or people waiting to be established as kohanim.