Have you tried "Helms deep reborn" survival map? It follows that design and doe's a very good job of it, as time goes on different events happen and you are pushed back from the walls into the keep etc.
Not Sure -
I did play one LOTR themed campaign which was pretty frustrating, tbh. It had one bit where you read a book on top of a well, then four tanks arrive.
Is that the same one?
It's survival only, but plays like a campaign really. I don't think I ever got far enough to see 4 tanks so can't really answer that :) It's good fun though.
Not the same one... I'll try and dig out the set since searching didn't turn it up.
It was multiple themes as I remember now; Tintin, the Mines of Moria, haunted house and a few others.
I'm getting old, I think it was L4D1.
does look pretty impressive in any case