The Steel Defender from the Battlesmith is more like a Golem than a Construct and looks really good too: https://www.gmbinder.com/share/-M8kCf8mUHGH4y2tx5i4 So I hope these Steel Watchers from Gortash are not Golems, because they just don't look like them. They really look like Constructs of an Artificer. I couldn't even imagine an Iron Golem like that. You can tell I'm too BG 2 biased.
Nice finding, the look of it has really some similarities with this steelwatcher !
As for who raised Gortash, I am tempted to answer Tymphal, the only archdevil known to be a mech genius and master smith & constructs
