I decided to rewatch DS9 season 1 to decide on my final order, and I was pleasantly surprised. Far from having dated I found its themes were only more relevant today, and while it certainly has its limitations (talky, lots of bottle shows, a bit dour in tone) it is a really strong first season of Star Trek. Stronger than Discovery, it must be said, even when for fairness I only considered the first 15 (so cutting off the masterpiece that is Duet but saving them the embarrassment of The Forsaken). The opening 4, Emissary 1 & 2, A Man Alone and Past Prologue, are all really excellent, as are the later Dax, The Passenger, and Battle Lines. Then you have Babel, Captive Pursuit, The Nagus and Vortex which all fit into the 'good' category. Only the flat Q-Less and the franchise-level stinker that is Move Along Home really let the side down in this first 15.
It's a really different tone to DSC, much less action orientated and light on revelations and twists, but I think it does a great job setting up the characters and telling some hard hitting stories. There are some notable similarities, too, like a solid tendency to call back to earlier Trek to cement a controversial new show into its franchise (Opening season we get O'Brien and Keiko, Picard, Vash, Q, and Lwaxana Troi along with a host of background references), a fresh new CO who will buck authority and bend the rules, a fresh-out-the-box obnoxious character who is shaped and molded by traumatic experiences, and a reimagined race (the Ferengi this time, freed from their furs and whips and placed in a confusing pastiche of capitalism-with-replicators) as a major but probably ill advised plotline.
So I would now put DSC third in the first season standings;
TOS > DS9 > DSC > VOY > ENT > TNG