S.M.
This summer I took some advice to send both boys to their rooms as soon as they started fighting, or if one tattled on the other. I don't ask who started it, or try to tell them a way to work it out - just off to their rooms. It didn't take very long for the fighting to drop wayyy down.
From experience, if you and your husband are not on the same page with the kids, discipline won't work, and they are going to act out a lot more. I found that when I was gone in the evenings the boys acted up more, too. I know you can't change that right now, and if you and your husband are working different shifts it's very hard to be a parenting team. But remember that you can be consistent during your time with the kids, even if he's not during his time. When he sees the kids responding to your requests more than his, hopefully he'll want to try it your way.