This might be solved by how you set up the party in the database. If whiplash is always going to be the leader, then you set up the initial party as him (her?) actor id #2, and trevor actor id #3. At the very beginning of the game, before the player sees anything, remove whiplash from the party so the player just has trevor. Then when you add whiplash back in, I think it will come back in ahead of trevor.
This is somewhat speculative. I know this definitely works when the 2 characters are id #1 and id #2, because that's how I've started my current project. I'm not sure that it will work if it's #2 and #3, but I think it's worth a try.
I am totally at a loss as to why you can't have an actor as id #1 and why it has to be blank for events to work. That may, or may not, mess up what I've suggested.