my boyfriend is mono.
and none of us had experience with poly.
We've lived together now for nearly 10 years.
I know other poly's who don't live together and are happy.
I would say it really is IMPOSSIBLE to define what will work and what won't-on a broad scale.
EVEN in "typical" monogamous relationships, there isn't a "typical". There's a typical PUBLIC persona-but behind closed doors-there's so many variables a person would keel over dead trying to reason them out to find the "perfect match for everyone".
We are each unique individuals and therefore, each "perfect coupling" will be different. In point of fact, "perfect" for me and DH is COMPLETELY different than "perfect" for me and bf. Because they are different, so what works perfectly in the couple-is different by the variables in which they differ.
EVEN IF I WERE MARRIED TO BF and DH was my BF-these differences would remain. I would not be "like I am with Maca" if I was married to GG. Because-GG and I have a totally different "perfect" and that would show up in differences in our marriage.
You're questions can't be solidly answered by anyone here regarding the example you gave-because we dont know the people in question. And, we can all give personal examples of what works for us-but they will all be different and very possibly-none of them will pertain to the example you gave-because we are all unique and our needs are all different.
"Love As Thou Wilt"