I love combining campaigns--I really do--I just get worried sometimes, that's all. Midian is my baby. I want to nurture it and watch it grow. I want it to succeed on its own, but at the same time, I don't want to see any harm befall it. I have largely consoled myself with the knowledge that I'm just a hypocritical bastard, the sort that would resort to lines like, "It's my damned game."
Then I figured it out. I know what my problem here is. I now understand what it is about mixing settings that makes me nervous, no matter how much I absolutely adore them, and the end results of the campaigns that use these. For the most part, this isn't mechanical: it's setting. I don't give a second thought to ignoring or changing anything mechanical in someone else's campaign. Hell, I do house-rulings on the fly all the time, with any game system. And if you haven't noticed, I frequently toss out variations and options for game mechanics for Midian.
Changing the setting, on the other hand, that's what makes me apprehensive. Now it's real to me. Whether your troupe uses 2D10s for attack and saving throws doesn't concern me in the slightest. That's great; go for it. I truly don't care. It's when you change the setting that you change the shared story. That's where my problem lies. I know, intellectually, that any changes that can be done can be readilly undone, but that's not sufficient on an emotional level. Just like a parent knows that their kid will quickly recover from a skinned knee, they still don't want to see their child hurt. Some part of them worries about scarring or tiny micro-injuries that will add up to their own creaking joints entirely too soon. That's the part that worries me about Midian.
Sigh. Sometimes, you just have to let your toddler play in the mud. They'll get hurt, but they'll grow and learn not to do that hurty thing again. I want to see my game grow and be built upon. I don't want to see it scraped up and altered. Growing is good; alterations aren't always so.
I'm not asking you to change things for me. That's actually harder to do, if you want it to come out right. I'm asking you to help me help the game grow. New details are good. New mechanical stuff is good. We can always use more classes, codicils, and the like. New setting stuff is great: new trade organisations, putting a village on the map, or adding an Elder Kingdom.
As overprotective as I am of my baby, please remember that it's your game, too. And I promise that I'll try to remember that fact as well.