I have some news: 2 Mythics just appear for the 3rd time whereas 4 others never appear in the Soul Forge:
So two solutions:
- easy one: change the weekly turn-over for a daily one so each week we can craft whatever Mythics that we want (until we have less than 24 Mythics, of course)
- other easy one: put them all, all the time
Nice, both are easy solutions, so why not doing it? 
No, honestly, players are paying dollars to fastly have 4k diamonds to craft Famine and no, they have to wait like other players to craft him? Is it part of your business plan?