A possible situation in a fleet engagement is redeploying a destroyer
screen. You have a core of ships with devastating long range capabilities
(graser-3's or HDC-2's) that have sacrificed close in firepower, so you have
a destroyer screen loaded with class-2 beams and submunition clusters to
make it really expensive for your enemy to close (Note: unless your opponent
has your equal in long range firepower, you really do want him to spend the
time to blow away your screen, as it keeps the range open). The problem is
having enough destroyers to completely encircle your core is equally
expensive, so you need to be able to keep your incomplete screen between
your enemy's fleet and your fleet's core. The formation may be too large to
just treat is as a single ship, and you may want to turn in one direction,
while rotating the screen in the other. Maybe your enemy has misjudged and
moved past your formation and you need to quickly get the screen to the
other side. Finally, as elements of the screen are destroyed, you need to
close up the gaps.
If you chose to go the HDC route for devastating long range firepower, you
really DO have to exert finicky control of your formation to keep the gaps
in your screen facing a likely enemy location.
BTW: I do not think grasers are unbalanced. At a distance they are quite
destructive, but at close ranges an equal mass of beam-2's cost less and
inflict more damage. They very much trade close in hitting power for long
range crunch.