Eh Football Manager is not really that intellectual tbh, even though at first glance there's a lot to it. And there is, but I took a team from the 8th tier in English football to Champions League glory and my tactics were basically to get my team playing well in 2 formations, 98% of the time used 4-4-2, to slightly alter my tactics whenever teams started beating me (I would change a specific thing and then change it back, once teams adapted), make sure I had 2 solid players per position for each of my formations, made sure to never play a high defensive line, to keep my wage structure under control, and.. luck. My team was the youngest in the EPL once I got there, took me 3 seasons to start dominating.. and I was still the youngest team in the league and had the lowest wage bill. Realistically my 21 and 22 year olds shouldn't have been able to compete with veterans, but in the game once you're on a roll, you're on a roll, and you keep winning. Plus the human player is given "the benefit of the doubt" it seems, so if you do most of the things "right", the game doesn't punish you, like reality might.
It's a fun game but I wouldn't call it overly intellectually challenging. Once you figure out the patterns you can take a crap team all the way to the top.
Besides, FM is very very addictive and can ruin lives.