Very good discussion here guys, but I just want to point out that managers in the game might have gone through different playing phases with the game. There can be times, where a player didn't take the game seriously or had long breaks from the game.

I am actually a perfect example, I play this game for almost 8 years now, started in April of 2013. However, the time when I was starting to enjoy the game, get a lot of knowledge on training and other things, and since then played it more seriously, was about 3 years ago in 2018.
When you take a look in my team showcase, there is a picture from my club history in Level 48, where I had 775 wins, 332 draws and 683 losses with only 12 league titles and 2 CL titles, which is actually horrible and for me would indicate an inactive player (which I probably was up to this point)... I remember when I was playing the game back then, buying expensive 5 star old players in auctions. The first round in cup would almost always be the end of my campaign then and I didn't know, that you could use rest packs for training players.

Today I am Level 84 and my club history is obviously still not the best, however my win % has improved significantly since then. Today I have 1400 wins more compared to my Level 48 stats, while only accumulating another 200 losses, which is actually decent in my opinion. If you only take the last year or so, the win % might even be a lot higher than this, because I had another 3 months break from the game in 2019.

I know some other people, who are like me. Who had this one moment, later in their "career", where they learned a lot about the game and thus improved a lot. Who today are very good managers and didn't want to start a new account just for better stats... So club record might be an indicator for how active someone is, but in higher levels especially, probably not the best. It's just a reflection of your past time. But what matters is the present, the current version of the opponent in front of you. And he might be a lot better than his records might tell. Or he might not be, because he is nowadays only playing the game casually and his greatest times, where he got the maximum enjoyment out of TE, might be in the past.