Combine Array of Sprites to Form One Sprite

Hi. I have an array of Sprite objects. Their sizes vary depending on the image loaded. I want to combine them side by side like a tiled map into one image. I want them to be layout like your are forming a line of images, one after the other. (note: NOT one on top of the other) How may I be able to do this?

The reason why I'm combining (just for those who want to know) is because I'm using a polygon2D Collider. Since there are some weird behaviors happening when I use multiple colliders side by side, I decided to just combine the images before adding one big polygon collider. Note that these things happen during runtime. I can't just create a big image and load that because the order of the images is only determined at runtime.

I hope to receive some help with this. Thanks.