Ok, I must have missed something.
Here I am playing along on my campaign, and sometimes I want a drop in, but quite often I don't. Basically it is either because the battles would be too lopsided (1000 troops vs 2 units is not fun for anyone) or the battles are too critical. Losing an entire campaign due to one loss is not something most people like. But the odd battle does happen that would be nice to see a player handle.
However, I do want to be the drop in person myself. But I don't really know when/where/how to do that. Do I have to sit in the MP lobby searching, or can I be pulled in while playing my own campaign. If the only the first, then I it's just not very fun for me, and I likely won't do it.
So basically, could someone spill it for me?