We see points of this with Ben and his spacewalk where he had some basic ability from his host. Sam showed the personality overlap in Oswald and when he and Al changed places. I am not sure if I like the use of an overlap to ease the story development, but Sam's incredible list of knowledge and abilities seemed almost superhuman. He was an MD, knew martial arts, etc. At this point, the need to bring the leaper through a wide variety of leapees and settings is a necessary part of the show.