so measured in weeks instead of the months it took for hit expansion 'Fate of Gundabad' to arrive.
It was a trench war but also more of a dwarven-style Blitzkrieg. Rather than just sit there for months the trenches and tunnels move forward pretty quickly :P
If that was weeks + resilience of the dwarves (so why they can still fight despite that previous war effort against Sauron), then not such a great "immersion" issue. If that was a story of men, however... that would change things.
I wanted to ask another question - how long do you think the campaign inside the mountain took? - but then I realized this is one of those "hard to define" since it doesn't have a definitive end, with all the dailies and missions being a part of it, and there is still some fighting even with Hrimil gone. Though I suppose... once you give us a date/event from the LOTR timeline, then we'll see how it is.