Wow . . . that's pretty horrifying.
It really is like an episode of hoarders. I dare say the painting skill all looks about the same which suggests its one strange bastard who is really painting all of this (poorly).
I can't even imagine the type of disposable income which would be required to amass such a Smaug-like mound of warhammer miniatures. There's some Dutch guy who slumbers on a pile of warhammer figures.
The only things I can imagine are:
1) he's wealthy, has a short attention span, and megalomaniacal factors
2) he's a GW manager who buys his own stock to keep his store in business
3) He's a mental case spending his assistance checks on warhammer. (I posit this sadly having worked in a FLGS where the 1st of the month a dude would come in and basically blow his welfare check on comics and collectables. Every month.)
4) maybe it's somebody collecting second hand armies, repainting them and reselling.
I fear it's number 3.. I tried to contact him once as he also had 5 chapters (Yes chapters i.e. 1000 marines each) + several titans from armorcast and GW for sale, but the responses I got were just downright weird. It is a shame though, seeing as how he treats the models and how little fun he seemed to have had with him.