Real ignored one of the most basic rules of the game. Some players only produce in certain environments. It's not just a question of ability. Rather, some players find a cocoon, a niche, which enables them to focus on one thing only, their job, and to maximize their productivity at the same time. It's comforting to know that soccer is not math.
Few players can guarantee top performances wherever they go.
I'm sure we can all cite dozens of examples of quality guys who flopped at some stage, for a variety of reasons. Yes, the level of play may be laughable, but his feats in Scotland border on the superhuman. Larsson has scored 84 goals in his last 111 matches. Those are monster numbers. And his contribution goes well beyond goals.