Look at the latest aerial of DHS' SWL and then take a look at this video:
If you think they can get to the point that DLR is in two months, I have very bad news for you. DLR started demo over 8 months before DHS. Yes, they have the River to deal with as well, but that is going to be open rather soon. And DLR historically works at a much faster pace than WDW. Not to mention they have dates that they NEED to hit to get the $1b from Anaheim. I don't see any way they open within 6 months of each other. But I also think that they are going to be dragging their feet to hold til 2019 at DLR. Another 18 months of construction would still only be Sept 2018, and based on where they are, that seems like a very achievable goal if they wanted to hit it.