What are those stats from, somewhere around 2019-2020 based on the player ages? It's kind of hard to say, unless the two players were developed in exactly the same way by the same person. Sometimes players never reach their full potential for one reason or another. Either they suffered a bad injury, or didn't get enough game time when they were developing, or weren't properly trained. So every save it could end up differently.
I remember in FM13, the saves where I didn't "rescue" De Sciglio from Milan, he never properly developed & maxed out at "fairly good". When I would buy him though he always became pretty much world class.