Will, there are 2 major issues of your testing and effect from these issues is so big that result of the tests has no connection with what people really get when they "normally" play the real game.
Here are these issues:
1) You aren't able to provide all tactics with a appropriate corner setup but tactics score about 35% of all goals from corners.
2) You may have all kind of players in your testing team but the problem is that assistant manager picks wrong players for the positon. He make crazy choices when there are much better options available.
Most funny thing is that the assistant manager rates all players very accurate when you look at players rating in "Squad Depth" and I almost always agree with such rating but on practice he makes anecdotal choices when he pick the team.
Do you remember Yilmaz? Just look how the assistant manager rate players for Shadow Striker role:
View attachment 816932
1) Eder.
2) Leo Baptistao.
3) Toivonen
As you can see Yilmaz is even absence from this list
but why do he pick him is a big mystery
...
Btw, it is easy to solve these issues and Ive already told you many times how to do that.