For you know how you ought to imitate us. For we didn't behave ourselves rebelliously among you,
Paul is doing once again what he has done on other occasions, that is, laying himself down as an example for others to follow (1 Corinthians 11:1). He is saying "ye ought to follow us: for we behaved not ourselves disorderly among you." It is disorderly, out of step, out of rank, not to work.