I think, in a given situation, when the time is right, Jefferson is ruthless. At the moment he hasn't really been in any opportunity to be. That's a part of him that comes when he is at his most desperate, and is lacking other choices and options. As it stands, in the beginning, he had placed himself in the most advantageous place--with Emma. He knew her more than anyone else in Marrowood, and he knew her to have the most power and potential. Kidnapping her wasn't necessary this time lol.
All of that has developed into more than what he bargained for, obviously. But even now he still believes that the growing OUAT cast and alliances are still his best bet which is also, amongst caring for them, why he remains within their group (safely nestled outside of it except for member meetings). He has, and still does, continue to make ties with those he deems worthy enough to be formidable assets (Jamie Moriarty, The Luteces, Stiles, James..)
Thank you *^* He was an unexpected love for me, and playing on all of the aspects of his character that arise during different points in time are both fun and difficult, and I'm glad that he is loved ♥