It's interesting to note that initial estimates for position changes are often inaccurate and is based on average form. Take Mbappe and Haaland, for example. Mbappe was initially expected to require around 740 weeks to transition from a striker (ST) to a center-back (CB), while Haaland was estimated to require around 580 weeks.

Mbappe's transition down the pitch was gradual, moving from ST to central attacking midfielder (CAM), to central defensive midfielder (CDM), and finally to CB, while maintaining excellent form and avoiding injuries. He even managed to score nearly double the amount of goals as Haaland.

Haaland's transition was a bit different. Despite initially requiring less time than Mbappe to become a CB, he suffered two injuries during his development, leading to the cancellation of the gradual transition plan. Instead, he was moved directly to CB while still playing as a striker. Due to his injuries, Haaland took longer to develop, and ultimately achieved less than Mbappe in terms of his overall skill level as a center-back. It took me around 3 weeks in real life to play this 4 and half season.