First we look at Barragan, who's ability cn rit anything with a physical form and lifespan, including spiritual bodies such as Shinigami which are comprised of reishi, meaning that his abilities can interact with it. 

Okay now here's the thing when we consider a lot of the Sternritters abilities to his own, there is no way that Barragan would lose, in order of who would lose Alphabetically for Irony, the Sternritter that would absolutely Die are. 

Pernida Parnkgjas because he wouldn't be able to get his nerve endings close enough to Barragan without them decaying away, and would spread to the rest of his body. 

Askin Nakk Le Varr, he would die because although he might be able to poison him from the distance overall, close proximity and long range attacks really don't have a whole lot of effect on him, i would imagine that Barragan if would be able to rather effectively rot away any form of toxic Rieatsu around him, and as for altering his blood I highly doubt that would be effective once he goes into his Ressurreccion form. 

Bambietta, would die, she wouldn't even really be able to be effective against him As any attack, she makes would probably rot away The closer it gets to him, this is due to the fact that her reishi bomb constructs require physical form in order for her to utilize said power, and I would imagine her death is probably one of the most boring as he would just simply attack her from a distance or if you wanted to be very vicious, just a clean dicapitation. 

Äs Nödt, he is dead, assuming Of course, that it's the same situation as Bambietta, he wouldn't be able to shoot his thorns at him because they would simply rot away, ultimately his only hope would come down to his Vollständig, and it would probably only enrage Barragan to the Point where he would try to kill him for his insolence. 

Now let's go rapid fire for the most obvious ones, Liltotto Lamperd Dead, Bazz B Dead, Cang Du Dead, Quilge Opie Close but he still ends up Dead, BG9 Dead, Pepe Waccabrada Dead, Robert Accutrone Dead, Driscoll Berci Dead, Meninas Mcallon Dead, Berenice Gabrielli Dead, Jerome Guizbatt Dead, Mask De Masculine and James Dead, Candice Catnipp Dead, NaNaNa Najahkoop DEAD. 

Gerard Valkyrie Suprisingly Dead, Gerard has an exploitable flaw, that being the Quincy Zeichen in his head that acts as his core, the second thing is that Barragam is a perfect counter to Gerards abilities, because not only is he a hollow and therefore poisonous to Gerard, but his literal power, is that Baraggan can age and deteriorate every object around him: even the very building he walks upon begins deteriorating from his mere presence, Because of this, he is protected from most close-range and melee attacks, for everything which comes within a specific range of him rapidly ages and disintegrates before actually making contact.

And that's even before he uses his Respira, which unleashes a black and purple smoke-like miasma, which radiates outward from him, ages, and rots anything which it comes into contact with. It moved fast enough to strike Suì-Fēng while she was attempting to escape from it at full speed. The miasma decayed the skin on Suì-Fēng's left arm until only shredded clothes and her arm's skeleton were left behind. Even after escaping the attack, the deterioration continued until the afflicted area was amputated. 

The only way this fight really goes between Gerard and Barragan is that he's going to continue being unable to actually fight with him, can't swing his sword because he's going to risk getting it rotted away from his mere presence can't slam into him with his fist or shield because then he could get exposed to his Respira, and he can't fight from a distance because regardless of whatever he could throw at him, let's say a building would get once again rotted away from his mere presence, his literal only choice in this fight is to flee, or to pray, because he can start severing limbs As much as he wants, which he will probably have to but it's not going to get rid of the poisoning effect that will happen from exposure to Barragan's power. 

Gremmy Thoumeaux, he's gonna end up dead. Ultimately, there are many ways that he might be able to possibly imagine killing Barragan, however no matter how he was to imagine them I highly doubt it would be effective against Barragan because of his own power, as Barragan's power it rots the very body and soul away, so imagining himself with an immortal body may be a powerful defense against Barragan's power but it's also a curse as since he would be unable to die his body would be covered in a power that would absolutely cause him to suffer greatly, additionally i don't image that Gremmy would be able to image a way fo kill Barragan easily, that he does the same method he did with Kenpachi, as well, in that case, he'd have to get close enough to Barragan to Enact it, and just like with Kenpachi's fight, if he doesn't make his body technically immortal, just like we saw in the fight with Kenpachi were he forgot to harden his body, in that case he's dead no matter what. 

Nianzol Weizol, ultimately , he's gonna end up dead, even though he can warp twist and bend space to his will, it's not gonna be very effective against Barragan who can attack from long distances, additionally there's also the prospect that when he tries to warp the attack he may accidentally touch it with his body and would die because of it, as we've already seen, his defense is not 100%. As He was able to be impaled by Senjumaru's needles, if it shows that there may be an obvious or exploitable flaw in his power. 

Lille Barro, he's probably gonna end up being one of these That has a fifty fifty chance of winning, and I think it comes down to whether or not Barragan in in his Ressurreccion, because if he's not then He might be able to kill Barragan with a shot from his rifle, but if he is in his Ressurreccion, then Lille is probably dead as his abilities regardless of the fact that can pierce anything would probably rot away before it reached him, Vollständig can be argued but ultimately it remains 50/50. 

Royd Lloyd and Loyd Llyod, Dead easily Dead, although they might be able to mimic his form and appearance, that's only eighty percent of his abilities and memories, there's also the fact that if they were to turn into a hollow , they might also poison themselves, so it would be very unwise to pit these two against Barragan who has access to a hundred percent of his abilities. 

Giselle Gwelle, Dead it's easily and laughably dead, Her blood rots away before it can get close enough to infect him, And he's probably just gonna kill her within like the first thirty seconds of meeting her. 

And so as it is currently, the only one's who really stands a chance against him are Uryu who would be able to swap all forms of damage and attack with Barragan turning his attack ultimately into his demise, Jugram Haschwalth who might be able to mortally wound him, This is assuming, of course, that he doesn't immediately get blitzed by Barragan, and Finally Yhwach, however.

I would go so far as to say. He would only win if the seal was broken during the time of their encounter, meaning if his eyes were still sealed. I feel like he would lose very easily, As his powers are at a stage where he would be unable to escape from Barragan's Respira, because he would be unable to find any alternate timeline to escape into, also one other fact is that we know that hollows are poisonous to Quincy's. And I don't see why that wouldn't be the same for Yhwach. 

This isn't really a Hot Take, more so an Observation, but if Barragan Lived, Almost if Not all of The Sternritter Would've Lost before the war began