Semi-Random Crunch - The Cavalry Line

I mentioned previously that I wanted to talk abou the cavalry line. I feel that the basic idea can already be found in the SRD, in a different context. I a cavalry line, each member would occupy less space than normal. What other rule is there that does the same? Squeezing!

A quote from the SRD:

Squeezing: In some cases, you may have to squeeze into or through an area that isn'’t as wide as the space you take up. You can squeeze through or into a space that is at least half as wide as your normal space. Each move into or through a narrow space counts as if it were 2 squares, and while squeezed in a narrow space you take a -4 penalty on attack rolls and a -–4 penalty to AC.
When a Large creature (which normally takes up four squares) squeezes into a space that'’s one square wide, the creature'’s miniature figure occupies two squares, centered on the line between the two squares. For a bigger creature, center the creature likewise in the area it squeezes into.
A creature can squeeze past an opponent while moving but it can'’t end its movement in an occupied square.
To squeeze through or into a space less than half your space'’s width, you must use the Escape Artist skill. You can'’t attack while using Escape Artist to squeeze through or into a narrow space, you take a -–4 penalty to AC, and you lose any Dexterity bonus to AC.

The -4 penalty to attacks and Armor Class is likely too high, and since the "obstacles" are not as solid and unmoving as a wall, it can easily be reduced.

Forming a Cavalry Line: Mounted characters trained in the Ride skill can form a cavalry line, as long as each member is trained in the skill. In a cavalry line, the spaces of two Large or larger mounts may overlap, as long as no mount completely shares the space of another mount. Each member of the cavalry line takes a -2 penalty on attack rolls and AC.

Example: Riders x, y, and z forming a cavalry line:

xyßz
xyßz

Rider x occupies the x and y squares. Rider y occupies the y and ß squares. Rider z occupies the ß and z squares.

Rider of the Line [General]
You are capable of fighting in a cavalry line more comfortably.
Prerequisites: Ride skill, Mounted Combat
Benefit: You do not suffer a penalty to your attack rolls while in a cavalry line.
Special: Fighters may take Rider of the Line as a fighter bonus feat.