I did parenting classes as we had a really horrific toddler who reacted really badly to the type of disciplining described here, and we were at our wit's end trying to manage him. He had fairly significant speech delay which was a big factor in his behaviour.
You haven't described anything like the kind of behaviour we were getting btw!
One of the tools was to praise praise praise when they were doing what you wanted, EVEN if it wasn't something you thought should be expected or done as a matter of course. Eg holding your hand, sitting quietly while you talk to Daddy, or here, ignoring your washing!
Another very useful tool, was to phrase instructions in terms of what you wanted done , so rather than say stop jumping around , you say, please sit still . Apparently kids find that easier to understand.
Both of those worked incredibly well for us.
A final one was to look at what was going on and to decide was this something important that you had to respond to. So say, holding hands on the street yes. Washing on the line would be a no from me tbh, but everyone has their own lines in the sand.
My dh didn't do the course which I was v cross about at the time (I did it privately as we were so worried, but we also got a free place through the health service here - Ireland); however he does defer to me now mostly in terms of how we discipline. Bit tiresome being the oracle on it, but at least it is consistent.
It was the Incredible Years course btw. There is a book, but it is very dense and not sure you could implement it without having gone through a course on it. A lot of it was quite counter intuitive, at least for me. It also focused quite a bit on how you were reacting to the child and how that was impacting on the behaviour. Spiraling off each other etc. That is harder to explain here but was definitely also a factor for us, our expectations were too high and we reacted too much to transgressions. It also dealt with clashes in parenting styles which you do have a bit.
So, for me, you don't have to go down a road of calling your very small children defiant (which is a bit negative and can be anxiety creating for yourself) and worrying your husband is ruining them by using a distracting method. That is also a valid method for children your ages. I still use it on mine - 6y and 8y now and they are not apparently ruined yet!