Mordecai comes from an earlier canon point here, as well. It's only by a few weeks, but they were fairly significant weeks since he was under arrest before coming.
Edmund has had some grumpy friends. He's known dwarves, after all. :c)
Marcus has been through too many wars, but he's a good guy. I think he and Clint could both like Echo.
Jac needs all the friends. She's still getting used to people not being like the majority of her family. She lives with her oldest brother, Ezra.
Eddie's young, but he's been trained as a bodyguard since he was little, and he's through a lot. He grew up with Rose and is a dhampir like her, but she is both ahead of him and has been here a lot longer. He's also a guardian, but neither of his charges are here right now.