The meta-analysis of all the dockets you propose would be a ginormous project
Even – or especially – taking citations as a Metacritic, this whole idea becomes unwieldy if you go beyond SCOTUS citing itself, for the sheer number of cases you'd have to review in creating it.
Let's take as an example why it works in science: the New Journal of Physics has an impact value of 3,539 in 2020. That's 3,539 recorded citations that go to articles in the journal on average per year. Assuming that this is about a tenth of the total output of all physics journals, this puts the total number of articles published by physicists on the scale of 35,000 per year. That is a somewhat manageable number created by a tight-knit community of very interlinked people. One might call their peer review process somewhat incestuous, but it allows one to make rough estimates on the total output.
On the other hand, the Justia New York State docket currently has about 350,000 cases filed. That's two orders of magnitude more than the impact factor of the New Journal of Physics for New York alone, and that only accounts for the tip of the iceberg of cases that get filed in New York, as Justia does not list all cases: it only takes federal cases. If you file in a lower court, it doesn't pop up there. It also only accounts very few cases before 2000 (in fact, the first 1999 case is on page 35,225 of 35,260). However, most cases start in the lower courts and stay in lower courts.
Traffic violations rarely leave the queue upwards, and small claims court is supposed to run down cases like clockwork and never to leave the low halls. In NYC, it's supposed to start twice a day 9:30 and 18:30 and attempts to get through as many cases per judge as it can. The time frame per case (anecdotal) is about 15 minutes. Assuming only one judge holds small claims for each of the two blocks and stays on the bench for about 3.5 hours, that'd be 24 cases a day per court per day, giving us a conservative estimate of at least 6,000 cases handled in a year per court. There are 11 of these courts in New York City alone, so the city alone produces about twice the output in small claims court cases as our estimate of total physics articles published in a year. And that's only the not noteworthy (and badly documented) level of small claims.
Now, back to the problem at hand: New York State has (on Justia) a docket that has, in total, an order of magnitude more cases as there are articles written in physics. That is a number that could potentially be skimmed by a supercomputer and checked for references to other cases. However, we have not just the New York State court, but we also have any other state courts. In total, there are 13 Circuits and SCOTUS to skim, though the last one has heard only 993 cases between October 2007 and October 2020, which incidentally is neglectable for the number of cases to review, even if these cases have a massively higher impact. However, our numbers rapidly rise in the sum up. Taking just the cases by the circuits from Justia (which by far isn't complete, as pointed out above):
- 1st Circuit, ~135000
- 2nd Circuit, ~440000
- 3rd Circuit, ~615000
- 4th Circuit, ~480000
- 5th Circuit, ~705000
- 6th Circuit, ~455000
- 7th Circuit, ~380000
- 8th Circuit, ~295000
- 9th Circuit, ~925000
- 10th Circuit, ~205000
- 11th Circuit, ~800000
- DC Circuit, ~60000
- Federal Circuit, ~35000
That's a total of something in the ballpark of 5,530,000 cases, just in these dockets. And that is by far not the total size of all the dockets, as those are, as mentioned above, just cases that are tried in the higher courts.
So, is it possible to do such a meta analysis, looking only for... let's say SCOTUS citations? No. Even assuming that we have only 993 SCOTUS cases that are citable and we only check the cases currently on Justia, we'd still review the complete filings of over five and a half million cases for any reference to any of them! The final decisions of some cases are some 150 pages long, some docket entries contain hundreds of entries, orders and documents, some contain even complete contracts as attached documents. This makes it almost impossible to make even a rough estimate of how many files would need to be sifted to sort these 993 cases by their relevancy – and that does totally ignore landmark cases that are not SCOTUS cases such as Browder v. Gayle, 142 F. Supp. 707 (1956) from the District Court for the Middle District of Alabama. Yes, it was a District Court with a panel of three that found bus segregation unconstitutional (though SCOTUS affirmed the decision as Gayle v. Browder, 352 U.S. 903 (1956)).
All in all, it would take Watson and a lot of time to go on this project and it might take years.