The power struggle

There are three students in the class that are constantly having power struggles with the teachers in the classroom. One student loves to push our buttons and power is something she is consistently trying to gain I think maybe because she has been so powerless in her early childhood situations. Another student is extremely sensitive, and he is sometimes like a time bomb at times. He gets easily frustrated and and then if he gets reprimanded he just shuts off and pouts. He blames it on being tired, and when you try to talk to him after he shuts off you can not get him to budge, it is difficult because the slightest things can set him off, but also the right word at the right time gets he back on track, and then he does good work. The other student is similar but when he doesn't want to do something he will get other students off track, or will do every obnoxious things like lie on the floor, shout, and fall out of his chair on purpose. He has some social deficits so he says certain things, that are hard to respond to and you usually have to just end up walking away. Power struggles are hard as a student teacher because it is hard to gage how hard to push. When you walk away from them do they think they won the power struggle? And Sometimes the students I mentioned need you to sit and talk to them for a good ten minutes before they will check back in, but sometimes they won't check back in and you have ran out of things to say to them. When students are rude to you it is hard at times to keep talking to them, especially when you feel like you are talking to a brick wall, but I guess that is all part of the power struggle. I'm started to fully understand the idea of differentiated instruction especially when it comes to discipline and power struggle with students.