Confusion regarding set piece instructions

[Weston]

I am confused by set piece instructions for a few different reasons.

 

When defending, how strong is the natural response your team has to opposition tactics if there are no instructions set, and, conversely, how static are instructions that are given? For example, if I set my defensive routine to have a short option marking player and the opposition doesn't use a short option is that player going to dutifully stand out there for no reason, or smartly change tactics? And if I set no routine and the opposition do use a short option how will I know for sure if a player of mine will react and go out there to mark even if the implemented instructions have him standing in the box? It is for these reasons I've always been scared to set any defensive routines and just blindly hope my team knows how to appropriately respond to different scenarios as they come up.

Similarly I am also confused about the player role instructions in general. If I set the set piece taker hierarchy to have Player A (my center mid) take corners but my corner routine instructs the left mid to take them, which overrides which? This often comes up if I sub on a player who is ranked higher than the current players on the pitch, or if I move the first choice kicker to a new position during the match. Why are these sorted differently - should we maybe assign corner instructions by player and not position as well?

It's all very confusing, and makes me feel like trying to make good instructions only opens myself up to more failure by giving specific but fallible and static instructions that would be avoided with simply letting the team do whatever is appropriate at the time beyond me designating the set piece taker. Do people go in tactics and completely revamp their set piece instructions every time they make a substitution, or is there just a way to say "the tallest guy on the pitch goes here" and let them sort that out as it happens?

Some clarity and/or guidance on these issues would be much appreciated!