The improvement on the shots of the Imperial Fleet approaching Hoth is astonishing and gorgeous! It makes the 2004 DVD look like good old VHS. Actually the quality of the 2004 DVD makes me believe Lucasfilm were trying to hide some weaknesses. However 1979 and 2010 cannot be compared in technical terms. Now that we have solved the technical weaknesses let's get down to some weaknesses of the shot in general. :-)
The Imperial fleet is approaching an unfriendly planet and everyone should have received the command: "battlestations". (except people commanded by Ozzel)
If that command had been given the star destroyers would not be that close to each other. Actually the shot looks like the Executor is doing a RAS (Replenishment at sea) with two star destoyers which endangers half of the fleet. When doing a RAS ships are most vulnerable as fire could hit and destroy all of them (http://www.marine.de/fileserving/PortalFiles/02DB070000000001/W26MUAG9296INFODE/EGV+BERLIN+beim+RAS_05_640.jpg ). Any RAS has the potential of a disaster, it's never a routine. The Executor has actually no reason to approach an unfriendly planet that close to friendly ships as it decreases the maneuverability of the flagship Executor!
If the Imperial fleet is on an attack mission they wouldn't be close together but instead far apart from each other! In the shot Lucasfilm established they are too close together. One, two, three shots of an ion cannon could do maximum damage as the ion cannon could fire at almost the same coordinates without major adjustment!
Ask yourself the question: If you were an Admiral where would you place your ships - Executor and 6 ISDs - if you know where the Rebel base is located?
I would position all those ISDs apart from each other leaving a corridor of destruction for all Rebel ships that will try to escape from Hoth.
That would render Episode 6 unnecessary, I guess. ;-)