
Army regulations do not have very descriptive specifications considering the wear of medals. It reads that it depends on the size of the jacket. The pictures show three and four wide rows. See the regulations and pictures below. However it is specific about not overlapping the full sized medals (though only when describing male's wear).
The following applies to the medal configuration in relation to the male gender.
Males wear full-size medals immediately above the left breast pocket, in as many rows as necessary. The number of medals worn in each row depends upon the size of the coat. Full-size decorations or medals will not overlap within a row.
These regulations refer to the female gender.
Females wear full-size medals centered on the left side of the coat. The bottom row of the medal pendants are positioned parallel to the bottom of the nameplate. Females may adjust the placement of the medals and nameplate to conform to individual body shape differences. The number of medals worn in each row depends upon the size of the coat.
Note:
It could be argued that females can overlap, but we have decided to not allow overlapping for the Army options.
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 Army blue and white uniforms. When the Army 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.
Our rack builder will give Army personnel an option of three or four wide. Many of the four wide mounts will just have one or two medals on the top row which looks funny but there is nothing against it in the regulations. See the examples of Army medal mounts below.

There are very few regulations that refer specifically to devices on full size medals. The device precedence can be assumed from the description of how they are worn on ribbons. See the following regulations concerning devices.
Oak leaf clusters, 13/32 inch in length, are worn on the suspension ribbon of full-size medals.
If four oak leaf clusters are worn on the suspension ribbon on either full-size or miniature medals, the fourth one is placed above the middle one in the row of three.
Note:
The previous are the only device regulations that specifically reference full size medals for the rest of the regulations please see the Army Ribbon 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 the fact that bronze and silver stars(campaign stars) are not mentioned in the regulations with concern to configuration, as is the same for the large gold stars and large silver stars.