I have some suggestions:
1. Subs dont have to be as good as your starting 11 because if your sub is the same asyour starting11 that means your overall quality is higher and you will face stronger oppoments in cup, league and CL after you promoted. It also cost a lot of cash and tokens to buy good players.

2.A striker's defence is also important because it includes heading, which is important when there is a corner, free kick or cross

3.MC needs defence in order to get higher possession

That's all. And the guide is really helpful to new users well done