You must stay in order with each player activating one character, but that character doesn't have to be the same from roind to round. So you may use your Survivor first in the 1st round and start with your Hero in the 2nd round.
So there is a way to activate the characters in the order you want each round. If my Hero needs to go before your Hero but you go before me, you just activate your Survivor first and I will activate my Hero first.
Hope that helps and is clear.
That clears it up, thanks! If the last player finishes their turn, after the refresh phase can that player choose to start? Or does it always start with the player that started the game?