you get closer and closer to the blizzard style with every icon you make. one additional element to take notice of is the framing and proportion. notice how your icon seems slightly more zoomed out than the ones you've shown in your comparison. minor differences that are hard to spot, but easy for viewers to subconsciously pick up on.
there is a rather noticeable perspective problem that makes his face look off. his nose, beard and right eye are drawn such they appear front-on from the viewer's perspective, whilst the rest of his head is angled slightly towards our left.
to get an idea of this incongruency, referring to this ref pic, lothar's nose should look like the nose on the far right. right now, it looks like the one on the far left.
I don't completely feel him, too. His face looks a bit deformed.
Although it's not your best icon, I really liked the embroidery you put on it.
They already told you the points to improve, so... I don't have anything else to say.