Atomatically put a list of picture in template

Is that one final combined image, or two hundred final combined images?

To put 200 image  on a wall would require 200 smart object layers that have perspective added to show a wall of image  in proper perspective. 200 Smart object layer is quite a load.  I have no idea of how well Photoshop will perform with 200 Smart object layers.  It may depend on your capabilities.  The way my Batch mockup script would also require you to setup 200 sub-folders the replacement images a queue of images for each smart object layer.     

My Photo collage template are limited to 53 Images because the Photoshop Alpha channel limit.  I did not know the limit was so low when I was developing my Photo College toolkit.  My Collage scripts can not add rotation perspective and warping to placed images.  The images are place in square to the canvas and masked to shape.  there is a single queue for all replacement images.

Because of this low 53 image limit and I knew some would want more image in a collage on a wall  or print more then 53 image on roll payer  I  programmed a script  Paste Image Roll.  The script can tile images on a canvas. All tiles will be the same size.   Image will be fitted to the tile size and pasted into the  tiled document.  200 Image would not be a problem.   Images can be fitter different ways.  Rotated for better fit and  resized to fill the tile where excess image content will be clipped off. Image will be like entered aspect ration crops. If you have a 3:2 aspect ratio camera and set a tile size the has a 2:3 or 3:2 aspect ratio the resizing will be perfect no image  content will be lost.

The Paste Image Roll script has as  simple dialog. Yous specific the resolution you want the document print resolution to be and the width relative the resolution in inches.   You cans set any resolution you want. A low resolution for web use is not an issue.  You specific the tile size relative to the resolution you set.  You can optionally specify inter image spacing and margins.  After you set the dialog you will be put into file selection dialog all images need to be in a single folder. You can Select as many images as you want 200 should not be a problem.  It will take some time to open 200 iages resizek them and paster the into a doument.  Here are collage 200 4"x6" portraits. 16.7' br 2'  , 4 row of 50 images.

There have been several threads on Scripts to replace Smart Object contents in templates and save copies. 

Do all the replacement images have the same size and resolution? 

https://community.adobe.com/t5/photoshop/batch-replace-smart-objects-v2/m-p/10324542?page=1#M227768

https://community.adobe.com/t5/photoshop/batch-replace-smart-objets-of-same-dimension-and-resolution/m-p/10260841?page=1#M220141

Please post the image in question or at least a meaningful screenshot.