I UP, it works perfectly well with two DDs, my eldest is an intense dramatic type, the second is more chilled out.
The usual conflict in our house is that DD2 wants to go out, DD1 doesn't. So, DD1 starts to kick off, I make a loud and silly noise to distract (she's 5 and it still works) and ask if we can talk about it. They know that we'll come up with a solution one way or another so will both come for a chat. I ask them both what they want to do and DD1 and I will come up with suggestions as to how we can do everything that everyone wants to do. Sometimes, DD2 will be happy if I go and play with her in the garden while DD1 stays indoors, sometimes I'll suggest a place to go that DD1 especially enjoys and she'll happily come out. Sometimes DD2 just wants to go for a walk (DD1 hates just going for a walk) so I'll take DD2 out when DP gets home from work.
There is always a way, it just sometimes takes us a while to figure it out. We don't talk about compromise (which basically means that no one gets what they want, but they both get something similar to what they want), we find ways that mean they can both have what they really want.
exoticfruits DD1 is emphatically not the sort of sensible child you are talking about, she's more the kind of child who has 2 hour long screaming fits about not getting what she wants. She used to do this a lot, but since we started using UP techniques she has learned that she can rely on us to do our very best to help her to get what she wants.