I have been searching for a tool to help me create mix & match makerspace challenges, in the same vein. I finally found one that I love! The tool is called Flippity, and amongst other things, it allows you to easily turn a Google spreadsheet into a random Mix & Match grid. Here is an example of a finished Mix & Match grid that you can demo. Clicking on the double arrows underneath each column you see, allows you to shuffle each column.
Using Flippity, I created a few different makerspace challenge Mix & Match grids for you to be able to see exactly how this tool might work for your makerspace!
Via John Evans