Qualities develop, flaws get fixed, both in the game and in real life
In real life, nothing changes overnight. A person doesn’t suddenly become super determined or get rid of all their flaws without hard work, time, and the right context. It should be the same in the game. There shouldn’t be direct trait swaps between players (like giving “Det” and taking “Err”). It would be much more realistic and logical to be able to remove a flaw or add a quality, but only when the player reaches a certain level, against a fee.
Concrete example:
You have a goalkeeper with the negative trait “Errors.” Meanwhile, he reaches a Total of 700, “Handling” over 90, and maintains consistent good form. You get the option to remove the “Errors” trait for 50 platinum funds, and it takes 10 days.
Similarly, a midfielder with steady progress and improved attributes can add traits like “Determination” or “Influencer” if certain conditions are met.
This way, traits are no longer fixed for life, but they also don’t change by chance. Players become valuable through development, and managers have a real reason to invest in them.