Hi! I think - not much changes are left to make the game really close to real football life.
One of the most important ones is adjusting AI priorities.
1. For example, when you play your last CL group stage game againt the team that has already qualified you will still most likely face the strongest eleven possible. Your opponenet's attitude won't differ from those matches where the result is in fact important.
Can this be changed? Every team has young players (hot prospects) and players that lack match practice. Is it possible to make AI change the squad in situations when the result is not impornant?
2. The same is about inner cup matches. In real life top flight clubs usually don't pay much attention to these competitions and their starting eleven in most cases differs form that playing in league and european matches.
When you're playing spanish season, you will always watch Real Madrid and Barcelona winning Spanish Cup. I played 14 seasons and there wasn't a single exeption. Real or Barcelona only. In real life for the last 10 years Real haven't won this competition. And Barcelona only managed to do it once. Usually teams of Zaragoza or Espanyol calibre win it. Simply because they pay more attention to this competion.
3. This is the one, that you definitely can change.
In Spain there is an almost universal tradition to play reserve goalkeepers in inner cup (Spanish Cup) matches. Most managers do that. Look into the statistics. This is a change that is easy for you to make. So please. This will be another step towards the realness of the game.
You will find in the database that many managers have a "tendency" when it comes to using youth/reserve players against lesser teams in unimportant cup matches. I would agree that this needs to be fine-tuned so that more managers do this.
Managers "tendencies" should be influenced by the boards expectations in that respect. Therefore if a club doesn't find the English Cup important, they switch to youth.
Unfortunately, i think the bigger problem is fixing the tendencies in the managers. If you follow the Premier League in England closely and watch how Alex Ferguson manages Man. Utd. in the game, you'll notice he will bench a fully fit Rooney in a league game from the start for Welbeck if he plays anyone who is positioned bellow tenth spot. This will usually send them to draw games stupidly, and then at the end of the season you notice they are 6th.