If they are all .dwg files in the same folder location, you can use the BlockChartxxx.lsp routines >here<. You navigate to the folder and pick any drawing file in it, and the commands bring everything in, spaced apart by a distance you can specify. Be sure to set drawing LIMITS appropriate to the width of a row or height of a column relative to the typical size of the drawings involved and approximately how many you would want in a row or column. See the comments at the top of the files.
EDIT: One thing to be aware of: If there are nested Blocks of the same name in the different files, defined differently in some than in others, the definition in the first file brought in will be used in all the others having the same Block name. So, say one of the drawings is BATHROOM1 that you plug into various apartment layouts, and another is BATHROOM2 used in others, and they both have a Block in them called TOILET. If TOILET in one is defined with zero rotation having the toilet aimed toward 0° [to the right] away from the wall, but in the other it's defined aiming at 90° [upward], then the definition in whichever of those BATHROOMx drawings was Inserted first will rule, and in the other BATHROOMy Insertions, toilets will face in some incorrect direction.
Likewise with things like Layers -- if there's a Layer name that is used in multiple .dwg files, but has different properties in different files, the properties in the first one Inserted will apply to that Layer in all those Inserted later. Also Text Styles, Dimension Styles, etc.
Kent Cooper, AIA