Hi Ed!
So I did a brief review of the “freeCodeCamp” page by Marina Ferreira that You linked to and soon discovered there is a “fly in the ointment”.
The shuffle routine depends on using a CSS flexbox grid. This grid depends on relative positioning. Hype uses absolute positioning. So we are swimming upstream here a bit. 
Here is a thread on this Forum regarding using flexbox. Attached just below is an example Hype project that @Did created and posted in that thread - pretty cool!
letsTryFlexBoxes.zip (24.7 KB)
Now You know as much as I do about flexbox in Hype.
This use of flexbox in Hype could be an interesting avenue to explore…
OR You could take another approach that more closely fits Hype’s “native” features. If all You are wanting to do is shuffle these cards You could write a JavaScript function that did that. “On Scene Load” could run that function - or the push of a “shuffle” button that would appear after all the cards were matched that could run the function.
OR for these few numbers of card sets to match - a timeline could do the job - no significant scripting needed.