Numbers in Freelancer can be Confusing, so here's a rough Idea for you:
Fleet
A Fleet is made up of two or more Task Forces and range in a number of sizes. Fleets are led by a highly skilled strategist and tacticians of maneuvering large numbers of vessels in battle. These Should be commanded by a Fleet Admiral or Admiral. For an idea of number of ships in a fleet is reasonably from 24 to 60 ships and possibly more!
Task Force
A Task Force is made up of two or three Battle Groups! Task Forces are led by seasoned strategists and tacticians who are given a specific role to fill in the Fleet of commanding war ships in support of the Fleet Admiral. Task Forces are commanded by an Admiral or Vice Admiral. For an idea of the number of ships would be 12-20
Battle Group
A Battle Group is made up of two or more lines.
Led by Commodore's a Battle Group plays an important role at projecting strength and bringing to bear a reasonable amount of weaponry.
Line
A Line is made up of One to Six vessels of various sizes.
These are commanded by Captains and Commanders who exercise the authority to lead their respective war ship(s) to combat.
A Line is a relative term for either a single large capital ship or a number of smaller ships.
For example a Battleship or Carrier and larger are typically viewed to be a single line unto themselves.
While several Cruisers or many frigates and corvettes can make up a line of 2-6 in size!
Snubcraft
Wing
A Wing is just a formation of two or more groups. Usually in size from 36 to 72 fighters or bombers. Commanded and led by a Captain or Commander
Group
A group is made up of a few squadrons. Usually in size of 12-36fighters or bombers. Commanded and led by a Commander or Lieutenant
Squadron
A Squadron is a group of craft such as bombers and fighters. These vary in size but often do not exceed more than 12 fighters or bombers. Usually led into battle by an officer of any rank depending on which squadron it is. For example if its the Commander of the Group's Squadron then he or she will likely being leading their own squadron. Lieutenants are often leaders of a Squadron unless there is a more senior officer with them.
Flight
One to Four crafts, ie fighters, bombers, often an Ensign or Lieutenant leads a Flight.
