Regarding fixing Lum’s MU against Arg:
I’m thinking that allowing Lum to draw off the bottom of the deck more often might be the thing. This is probably best done by tweaking Roll The Dice, but it could easily be a part of Jackpot too, although not so easily with the proposed Jackpot change.
Regarding the proposed change to Jackpot, turning over two cards and only drawing on hits: I think I like it, but thinking about this change is tying me in knots. It is both possibly too strong on damage and too weak on card cycling. I’m pretty sure it would be a big change to Lum’s play, so it’s hard to say how it would go.