Since I only play PVP, I can only give you an answer from this aspect. If you're not good at making changes to the whole structure, take out a winger. Whatever the formation, taking out a winger has the least impact. If you want to go a step further, you can take the remaining winger back and make changes to the defensive midfield combination and the role selection of full-backs. With good adjustment, you may not even feel the impact.
The core of FM24's top tactics should be the DM-S+DM-S combination, which is more stable and has a higher limit than other defensive midfielders, which I have experienced especially in online games. This tactic is also the one I use most in online matches.
only "Tackle Harder" in every position，I think other than the key PI of "Get Further Forward" and "Move Into Channels", it's hard to say how much difference will be made.
Since I only play PVP, I can only give you an answer from this aspect. If you're not good at making changes to the whole structure, take out a winger. Whatever the formation, taking out a winger has the least impact. If you want to go a step further, you can take the remaining winger back and make changes to the defensive midfield combination and the role selection of full-backs. With good adjustment, you may not even feel the impact.
only "Tackle Harder" in every position，I think other than the key PI of "Get Further Forward" and "Move Into Channels", it's hard to say how much difference will be made.
Remove "focus play down the right/left"
Remove "underlap right/left"