So I've been trying to solve this for a while and this thread is what comes up when I Google search, so now that I personally found a solution, I thought I'd go ahead and post it on this year old threat for anyone looking for a solution.

If you trying to make a trust NPC the party leader, it automatically dismisses them all.

So you can use party command macros to dismiss them. So you can use a single macro to dismiss and resummon all of them.

For example, my macro is:

/pcmd leader Trion
/pcmd leader Ulmia <wait 3>
/ma "Trion" <me> <wait 6>
/ma "Ulmia" <me> <wait 6>
/ma "Cherukiki" <me> <wait 6>
/ma "Shantotto <me>

It's not necessary to have two /pcmd commands, but I put it in in the event that one or the other of the Trust NPCs dies so that it still works.