...the one concerning subpoenas to Mazars & Deutsche Bank et al.
That case is not about a president defying a congressional subpoena, SCOTUS already unanimously ruled in 1973 that the president (Nixon) has to comply with congressional subpoenas (& turn over the tapes).
That case is about congressional subpoenas going to 3rd parties (Mazars, Deutsche Bank, etc) & POTUS stepping in & trying to prevent 3rd parties from complying with those subpoenas.
To me that makes that case a VERY different animal, because if SCOTUS rules POTUS has the power to stop 3rd parties from complying with subpoenas, then POTUS can use that power to hide his own crimes, or the crimes of those in his administration, or family, or friends.
For example, say the president's brother shoots & kills someone. There are several witnesses, but the key piece of evidence is a convenience store surveillance video recording that clearly captured it all. Prosecutors subpoena the video recording. Does POTUS have the power to step in & prevent the convienence store (a 3rd party) from complying with the subpoena, in an effort to save his brother & his own reputation (POTUS desperately doesn't want the stigma of having a brother that's a convicted murderer)?
Yes, I know there are key differences between the actual case & my example, I chose it specifically to illustrate how dangerous it would be to give POTUS broad powers to block 3rd party subpoenas.