Exactly, i would put my oven to the lowest temp (warm) turn it on and warm it up. Once my strike water is up to temp, i put my grains into the pot, turn off the oven and put the pot into the oven. It will hold a solid temp around 155 without any problem.
When doing partial mash, 2-row is included in the grain bill as opposed to extract kits only have specialty grains. Extract is essentially a condensed form of barley. So when you steep with some 2-row you are getting sugars from the barley and need less LME to reach your O.G.