From my somewhat limited understanding of Kurito, you get some combination of what is available at each tier. Your experience there seems to verify that fact.
You only got one CR?
If you got a CR, that's definitely worth it from a shard perspective. I'm more interested in finally getting the SR card, but I've yet to figure out a combination that gives me the highest chance at getting her. I've tried combinations that added up to approximately 10,050 two times, but I didn't get her either time. I did, however, get some puddings and maybe a CR.
We're actually getting more into the crux of the other thread that I started a while ago which is trying to crowd source data from Kurito. The wiki is as accurate as the data on hand. IF more of us kept track of what we offered and what we got, we would eventually get a pretty good snapshot of what the rewards are and how frequently they appear. It would also tell you whether it is more efficient to spend shards on EX Wilds or CRs since you can feed 5 EX Wilds and get a CR + R gachas. While it's true that you will not get that every time, it's possible that it's more common than puddings. Or maybe puddings is more common. Or maybe they are equally probable. Then it's up to the person to determine which is more valuable: puddings or CRs. But the general idea is the same. You figure out what you're likely to get based on what you spend to determine the best course of action.