I like Option E.
The 2 random sets seems like it would be challenging and may provide some creative and useful combinations that normally wouldn't be seen in the game play we have now.
Personally so far I enjoyed using the Untamed deck the most and having a league on its own I suppose would be alot of fun and also may boost usability in the way that the cards I previously acquired would be more important to me to keep in my playables; while also potentially helping to keep the cards more in demand then before.
You get it!! This a big part of the point of this option... expanding game dynamics and the fun/excitement element!! And keeping older editions relevant with real use cases!