I have 3: a DE MM, a mono MM that I just purchased, and a PM in azure. I know that some people are scornful of the Neverful because they are so commonly seen, but there is a reason they are so popular. I enjoy mine.
I have a mono GM but I think as many of them that still make you happy. I'm not a tote girl but I do have more than one Speedy as well as the Montaigne and Alma which are pretty similar styles to the Speedy. They all are a bit different and still make me happy.
I have a DE MM but a mono GM is definitely on my list. And possible an MM in DA. With the lining color options now, there's endless choices! Luckily I'm only interested in the canvas...
I have a DE in GM and a mono in MM. I'm satisfied with both but have thought about buying a preloved mono in GM. The added pouch/clutch is not worth the price on the newer models IMO. I doubt I will ever use it and apparently most don't. That's why I see them for resell EVERYWHERE.
I think 2 is enough. I rather venture and try other styles.
Currently I have the limited edition Stephen Sprouse rose NF. Not thinking about adding another one.