Currently I've been working on getting my five year old son and three year old daughter to "use your words" when resolving conflicts with one another. It's a work in progress. My wife and I are making headway though. Our son has gone from consistently getting physical in conflicts with his sister to whining that he needs help with her, and actually, but rarely, stopping to tell her what she is doing that is bothering him and then asking her to do some other activity. Frustratingly slow, but extremely rewarding.
When you get right down to it, "raising kids" is probably the best answer to this question that there is. Most intense/rewarding collaborative experience in the world. We're thinking about making the jump from one to two. Is it way more intense?
Important work, seemingly never ending I would imagine. I have been working on "use your words" with my 2 year old. It's getting better, but a good long scream often surfaces in place of "Daddy, can I please have more "X". Throw another child in to the mix and now you're working on multiple fronts... -Sounds difficult but like you said it also sounds rewarding. Good luck.