I've had players with tsp over 120 and I've never even played higher than division III, and right now I got 22 year old with tsp=91 and still going up, so it is very realistic to reach tsp=140. I'm not saying it's common or easy to do, but hey, it's not easy or common to be LeBron or Curry either. If you don't believe me check transfer market, there is plenty of players with tsp over 120 and even over 140. Here is an example
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