On the other hands, games in general made many weird book-to-game transitions for the sake of gameplay. From introducing stuff like meditation (and no sleep), over alchemy which while often entertaining is fairly wonky, to Signs which are absolute joke - from becoming a fairly simple magic tool to full-blown sorcery and Jedi mind tricks. It also introduced bombs and crossbow, but at least their introduction isn't overly jarring.
Similar goes for stuff like forging swords and armors - the first game was probably the best in that regard, since it offered very little in terms of loot but was more faithful to the books - Geralt, in essence, carries a leather jacket, a sword, knife and his wits and reflexes into battle - everything else comes before it. But, you know, players demanded more loot and customization so you get more stuff in sequels. At least TW3 introduced Witcher gear which was best IMO and made most of the other stuff redundant, at least after early game.