RE: Pairwork
I have two very different classes. I let my S2s sit however they want. They're at that rebellious age so, if I wanted to assign Serena and Vivian to work together, I'd have to tell them, [Putting on Stern Face] "Now whatever you do Serena, DO NOT sit with Vivian!"
For my S1s, I put my two strongest students together so they have someone to compete with AND so that, a weaker student can't "slide" by letting them do all the work.
The others I do by a combination of ability and personality. I put my lowest level boy with the cutest, mid-high level girl. I know another boy has a crush on Roxy, so, of course, I put them together. In Xuzhou, it's customary for a married couple to give a fish to the person that introduced them. I plan on getting lots of fish!! Not really...
And like you, I always switch them around. I've added two things that have helped, well I've changed several things, actually. I've replaced "Raise hands before leaving seat" and "Make smart choices" with "Speak English" and "Take Notes". Those two weren't problems for me, I didn't get "BAD" behavior, just NO behavior!
I also added: Class-Talk. It's just like Teach-OK, except that during Teach-OK, I'm trying to teach a concept that is not usually language related so I let them use Chinese if they either don't know how to say it in English or their classmate doesn't understand. CLT anathema, I know! But in Class-Talk, they MUST use English.
To encourage (read "make") the students listen to each other (How many times have you answered the same question 3 times in the space of five minutes?), whenever a student has a question, I do a Class-Yes and say "Malisha has a question." The class then does like a "Hands and Eyes" but their focus is on Malisha. Class goes, "Yes, Malisha?" I then do a mini-lecture to answer the question followed by a quick Class-Teach, then resume the task at hand.
How old are your kids? What are you doing differently? What's your motivator? Which scoreboard are you using?