> everyone who knows which president nominated which justice knows what the outcome will be
People commonly predict SCOTUS outcomes by knowing the judicial philosophies of the justices, but "which president nominated" them is a pretty poor determinant for how they'll rule.
Gamble v US had Ginsburg and Gorsuch paired up in dissent, with Kavanaugh in the majority despite both Gorsuch and Kavanaugh having been Trump appointees. Kavanaugh and Gorsuch have been at odds in many cases. Reed v Goertz, Turkiye Halk Bank, Bittner, Apple v Pepper, Myers v US, Murphy v Collier, Price v Dunn, and others that aren't immediately to hand.
Adding in Amy Coney Barrett, and ignoring unanimous decisions, it's very hard to find cases in which Kav, Gorsuch, and Barrett are all in agreement. Beyond that, it's worth remembering that in any given term, cases are decided unanimously between one to two thirds of the time, and while there are outliers, tight partisan splits are generally about a quarter of the time or less in recent history.
Sotomayor and Kagan represent the high-water mark for recent appointees being in agreement at 94% of the time, but fwiw, altogether Kagan and Roberts end up on the same side roughly 75% of the time.