
Marine Corps regulations are rather descriptive concerning full size medal wear, there is not much interpretation to do.
The following applies to the medal configuration in relation to the male gender.
For men, the maximum width of the holding bar for large medals will be 5-3/4 inches, and the length of the medals from top of holding bar to bottom of medallions will be 3-1/4 inches. A maximum of four large medals side by side will fit on the maximum width of holding bar; however, a maximum of seven medals will fit on the holding bar if overlapped. The overlapping on each row will be equal (not to exceed 50 percent). The right or inboard medal will show in full.

These regulations refer to the female gender.
Women will wear no more than three large medals side by side on a single holding bar not to exceed 4-1/4 inches; however, a maximum of five medals will fit on the holding bar if overlapped.

This describes medal configuration specifications.
Personnel wear all full-size decorations, in the order of precedence from the wearer’s right to left, in one or more rows, with 1⁄8-inch space between rows. Second and subsequent rows will not contain more medals than the row below.
The following relates to wearing unit awards with medals.
Personnel may wear U.S. and foreign unit award emblems as prescribed, when wearing full-size medals.
You may wear medals on the following uniforms.
All personnel may wear full-size decorations and service medals on the Marine Corps blue and white uniforms. When the Marine Corps green dress uniform is worn to social functions, enlisted personnel may wear full-size decorations and service medals on the coat of the green dress uniform.
See the maximum number of medals per row for females on the left and the maximum for males on the right.

Place devices vertically in precedence from the top down.
On suspension ribbons of large/miniature medals, stars are placed with one ray of each star pointing up. If one star is authorized, it will be centered on the suspension ribbon. For more than one star, they will be evenly spaced in a vertical line at the center of the suspension ribbon with the senior star uppermost.
The V device will be placed below stars and oak leaves.
Only one "V" will be worn. Gold, bronze, or silver stars, or oak leaf clusters worn to indicate subsequent awards are evenly spaced in a vertical line above the "V" at the center of suspension ribbons of large and miniature medals.
Use large oak leaf clusters.
If a second or subsequent award of a personal military decoration or the Joint Meritorious Unit Award is bestowed upon a Marine by the Department of Defense, Army, or Air Force, a bronze (or silver) twig of four oak leaves with three acorns on the stem, 13/32 inch in length is worn on the suspension ribbon of the large medal.
Below are examples of full size medals with devices taken from the regulations.

As for the rack builder we interpret the regulations concerning full size medals as follows:
Note:
These interpretations are based on physical spacing on the suspension ribbon and Marine Corps regulation.