I think Vardy being in the side is a real plus, but really they're just doing what they've done all season but are now getting the rub of the green a bit more. Even in this game Swansea had nothing bar the Oliveira effort and because he's been honest and stayed on his feet, Leicester have won the game in the end. If he'd gone down they'd have got a penalty and probably be up against 10 men.
Also Huth has been a good signing, he's played every game since coming in and although quality wise the big German is nothing to wet your pants about, it means that the changes in formation, often playing a back 3 with enough players comfortable to do so, and being able to change during play is now working effectively. Pearson has made big changes in the formation this season that weren't necessary in the championship, and I think him and the team are finally getting to grips with it.