Set piece positions changing during a game

[TacoCorp]

Is there a way to avoid your set piece instructions changing during a game?

During a recent game where I was forced to move a bunch of players around when making some difficult substitutions, I found it odd that my Assistant Manager was telling me off for not having anyone marking posts on corners.

I had moved my DL and DR into midfield and then substituted the replaced midfielders with DL/DR from my bench. When I checked my set pieces, sure enough my DL/DR were no longer set to mark the posts.

Is there any way to make it so that the set pieces don't change during a match and whomever is in the position will continue to perform that role?

[Fritz13]

So the positions no longer existed within the tactic but the players did if that makes sense