I think there must have been something about the combination of JNT and Eric Saward that meant Peri gets treated very badly in many of her stories. It's a bit like Sarah endlessly getting hypnotised and sacrificed but at least you can see that is a legacy of the horror tropes they are aping - it's harder to figure out why Peri is endlessly threatened with disfiguration and rape and ends up in a forced marriage, though it is also true that the combative relationship they chose to depict between the Doctor and Peri in S22 didn't help the character any either.