In short, yes. If you don't name an affirmative defense you can't use it later on, hence the shotgun approach. Better to have it and not need it rather than need it and not have it.Is this usual in law where it looks like the parent is standing there asking a child why the cookie jar is smashed and they just rattle off excuses that end up contradicting their previous excuses?
"We didn't do anything"
"He already had a bad rep"
"He brought it on himself"
"We had nothing to do with this, it was them"
"But it was all true!"
"It was just rumors"
"It was just banter"
And even if they contradict each other (for example, "It's not defamation because it was true," and "it's not defamation because it was opinion") the defenses don't impeach each other.