on the topic about cinccino, it will get worn down more easily over the course of the match than glaceon will, simply owing to the fact that it's also susceptible to all kinds of hazards. the difference is that there is no way cinccino is gaining back the hp.
first of all, if cinccino comes in as glaceon uses substitute and protect, then glaceon will be able to scout it and gain all the hp back the next turn and switch out. cinccino basically just lost 24% hp (assuming stealth rock is up). if cinccino uses u-turn or switches out of whatever comes in, then it has to take another 12% and possibly more hail damage later in the match. if cinccino comes in after a kill, similar situation except it loses like 18% hp which still racks up.
then there's the fact that cinccino is most likely going to be holding a life orb or choice item. yeah king's rock is possible, but the others are far from relevant. life orb just stacks even more damage, so cinccino will be taking around 1/3 of it's hp just to have glaceon switch out and be preserved. a choice item means that you're predicting even moreso than the glaceon user has to.
of course the glaceon user does need to predict between using substitute or an attack at times, but the fact that it can recover back its hp and that it's likely for a competent hail team to carry a cinccino check means that it's cinccino who will be more pressured since it dislikes residual damage more. it's a double-edged sword; both users have to play around each others' threats, but glaceon will have the better end of the deal. also using a specially defensive spread on armaldo and garbodor is actually pretty niche honestly. there's no reason to actually give them a spread like that.
i'm not going to say that glaceon doesn't have its own problems since it doesn't switch in so easily to many things as well, but at best, cinccino is a shaky check and really isn't an end-all-be-all answer to hail.
also, to be quite honest, if it really comes down to glaceon having to stay in on cinccino, it still wins if it has a substitute up. cinccino will be using two hits for the substitute. it won't KO glaceon while cinccino is OHKO'd in return with blizzard.
252Atk Life Orb Cinccino (Neutral) Rock Blast vs 112HP/0Def Glaceon (Neutral): 90% - 107% (270 - 320 HP). Guaranteed 2HKO. 42% chance to OHKO. (this is for five hits with glaceon having no substitute)
i'm lazy to type out more, so here:
[16:15:59] <@ebeast> each rock blast hit does 20% on average
[16:16:04] <@ebeast> so 2 to break sub
[16:16:12] <@ebeast> you take 60%ish from the rest
[16:16:20] <@ebeast> get 12% back from ice body and lefties
[16:16:28] <@FLCL> gfg
[16:17:20] <@ebeast> so you're left with 52%