In our 300 point lists, most people generally field around three capital ships. There are some lists that mix this up, but by and large, you either see three ships, or two large ones with many squadrons. In this situation, what I've noticed is the best strategies generally involved getting the first kill. In a 3 ship vs 3 ship match, losing a ship before your opponent does generally seals your fate, unless you somehow manage to do enough damage so that you can have a counter attack that removes two of their ships. That's really rather rare though. First person to lose a major ship tends to lose the match, whether it's losing your Demolisher, VSD, or AFmkII, whatever.
With us moving to 400 points, I believe this is going to change drastically. Four ships will more than likely be the minimum, with quite a few lists fielding five or more. Of course, this is dependent upon the size of ship, especially considering now that we have the large ships that'll eat up equivalent percentages of your list as medium ships did in the 300 point lists. What I see happening, however, are multiple engagements. Focusing your entire fleet onto one enemy ship in order to gain an advantage won't be quite as helpful, unless your enemy has a Large ship stacked with upgrades and their commander. Focusing one enemy ship worked at 300 since there was less opportunity for your opponent to counter-attack. With 400 points, focusing on one enemy ship leaves the rest of the enemy fleet, which is now a more sizeable portion, the ability to gain much better positioning, and more easily come back from an early set-back.
Consequently, I believe that, moving forward, the best strategy to implement will be smaller sub-groups within list builds, each of which can go after an enemy target on its own. An example would be a Demolisher paired with an Overload-Raider. These two ships make up a bit more than 1/3 of your points (depending on how you decide to kit them out), but by themselves are capable of quickly destroying a medium sized ship on your opponent's side. An Imperial could quite easily destroy a small ship in one round of shooting, especially if it manages to get a double-arc.
Doing this would also mitigate your own losses, if your opponent gets one of your ships early on. With a more compartmentalized strategy, your sub-groups are less effected by losses suffered in other sub-groups.