The way I see it is: Temporum did what you're describing, at got lots of flak for it. There are three necessary mechanics in it, and it's laid out such that each board has those three mechanics. And Dice Tower was all, "These cards feels too samey, bloo hoo hoo!"
I think Dominion does about as good a job as it can with making Kingdom cards more desirable than Silver and Gold. I do agree that it would be nice to have a mode online that e.g. pulls 5 cards from each of two random expansions, for folks who like to see more of the intra-set interactions. I wish Shuffle iT could somehow make that happen, but man they're so far behind with priorities that are so much greater (good animations, offline support, etc.).
Aeon's End does fine without basic cards. Quarriors has the starting dice in the supply but I've never seen anyone get more of them. Maybe those games would break under the scrutiny Dominion gets here, maybe not.
"Kingdom cards more desirable than Silver and Gold" isn't really what I'm getting at. It's more like kingdom cards that make other kingdom cards more/less desirable. Like splitters and non-terminal actions "play well with others" in an obvious way; if the kingdom lacks those, you'll tend to use fewer kingdom cards and probably more Silver.
5 from each of two sets might be cool. I proposed in another thread a mode where for an N-player game, you get 10-N at random, then each player picks one card (after seeing the random cards). I'm curious what you think of that, but also agree that ShuffleIt has higher priorities.
