This is where the long angular pasterns have come from. I also don't find his movement all that spectacular.
The sire's sire line is a common line as the "W" that came from the "F" line and reverted back to the "F" line is not that highly sought after. Some decent jumpers have come from that line and a few dressage horses but this particular sub line in not very well known and not a sought after line (Weingau is probably the only one with any real credentials).
The sire's dam line originated with the TB Vollkorn and did not become an established line ( at least in the main Hanoverian production line).
The Dutch stallion Nimmerdor is the one that you can say is the best contributor to good blood and in the area of jumper mostly.
Grand Casso dam line also includes the Trakehner line but it also appears to be there for refinement only and nothing of note has come from this line.
So if the OP was looking for a dressage horse nothing from this sire even whispers dressage. Mostly jumper and there is again the pasterns of Joey certainly look like they came from the sire.