I'm not sure it would be any different docking
a twin wheel as opposed to a single
I have a 47' center cockpit
with a skeg hung rudder
and have no problem docking it but it does require having a good handle on being able to figure where you are in relationship to the hard land based objects since you can't really see how close you are. You just have to be able to visualize your position.
The only advantage I've found on the twin wheel boats I've sailed is the visibility afforded when going to wind
and the ease of entry in twin wheel boats with swim platform/stepped sterns. Then again the trend toward smaller headsails and bigger mains has helped forward visibility too.
On the newer designs with their wide sterns it's an answer to a problem, mostly it's what the customer wants, a big cockpit
and plenty of space down below. How that relates in sailing terms is a whole nother story, I do know that the boats I've sailed with wider sterns that they tended to be a little more work
going down wind
with a good size following sea, but that may just have been that particular boat. I can't comment on the 400.