Here's my very quick example for this week:
http://omniplex.articulate-online.com/9115222693It's a course with multiple question banks and uses a random number generator to select the order in which they are presented.
This can be adjusted by changing the #2 in the javascript to match the number of QBs, and increasing the number of navigation triggers accordingly - including on the feedback layers for the final question in the bank. If you have multiple questions in your banks you might need to lock the final question.
But, all in all, it's a scaleable solution, we've done this with client courses with higher numbers of banks.
H
Edit: link to the thread containing the source file:
https://community.articulate.com/discussions/articulate-storyline/elh-challenge-132-javascript#reply-358890