Players often forgot that trusts have no AI, its not a smart system, its a fully written script on how a npc will react at any given moment.
This is why certain events will always play out the same way. The npc does not see the aoe on the floor but the script for the aoe is connected to the npc avoiding it.

Squadron is a "cover all" solution, its a general written script that may or may not work for the content you do.

So by asking for trusts for all old content you dont ask them to copy a script but to write a script for each dungeon which can be a big task.
Trusts are more akin to a solo duty that was fully planed out before you even enter, and you simply play your role.

keep in mind trusts are not "smart" they just are told what to do what happens before it does.