A.G.R.A.E.L., the issue probably wasn't caused by the patch, but rather by starting a new game. In general, it's best to specify the location. There are maps where you can reach another player's Castle in a week. As for where such an army came from, you can only guess. Neutral creatures might have joined. Although, they never joined me unless I had a strength advantage. It's possible that a mod was installed. For example, one that allows you to recruit heroes from campaigns. With a single skeleton, Marcellus wouldn't be able to attract a legion of dragons, let alone units of level 4 or 5. Another possibility is that the scenario starts with a Castle that is not level 1.