Outdated Villagers in Mash-Up Packs

In some of the Minecraft Mash-Up packs, I noticed that many of the villagers have an outdated trading system and overall more broken interactions with the game than the updated regular version. I’ve tested it with the few mash-up packs I have—specifically Greek myth, Egyptian myth, and Chinese myth, and all I’ve found to have somewhat broken or outdated systems.