I will wait for QC to decide what ev spread although i am pretty much convinced 232 hp is optimal.
i dont expect super fang to be here for long (honestly it only hits a handful of steels and they have to be dumb to slowly let themselves get ko'd by it). you miss out on way too much (ZAPDOOOOSSSS)
I dont understand why you want me to talk about Toxic in set comments but you also dont't want it to be in the set.
i added Roserade and mentioned how she can set up toxic Spikes absorb grass moves but I think the sleep powder thing isn't worth a mention since a sleeping poke isn't going to stay in 9 times out of 10 in my experience so walrein doesn't ever get that free set up.
Walrein only has trouble with fighting mons if he hasn't set up yet otherwise he handily beats them all except bu scrafty which can't even 2hko walrein iirc. I dont feel a need to add even more partners to cover the fighting weakness when a team in general already should cover these threats. Its like saying "rayquaza is sd normal arceus weak so have a way to cover that for your team" well duh every team should have a sd arceus counter in ubers (i do play ubers its fun C:) or it will destroy you.
i added the Rapid spin mention although i have yet to decide what the spinner should be...claydol and hitmontop are like mediocre at best while Blastoise is a good spinner for hail stall i find but for the purposes of this analysis (a walrein analysis not a hail stall analysis) it doesn't work terribly well with Walrein.
I guess Gligar and Cobalion make sense to set up SR they just never really stood out to me as good partners, just random sr users.
I might mention the offensive late game cleaners but I stressed several times how this was supposed to be on hail stall only where you won't see many of these attackers. And Nidoking won't go too well if you use Nidoqueen I am guessing (although who knows).