Firstly, I can clearly see that this team is built around Moltres + Comfey, alongside other Meta Mons such as Landorus, Fini, Eleki and Kartana. As you mentioned, Glastrier is a huge problem for the team and is one of the most ubiquitous mons out there.
One of the most recent gimmicks/duo that has been hugely successfully for me, personally, and many others is Zapdos + Grimmsnarl. Instead of building around Moltres + Comfey, which it slightly difficult to use as it can easily be revenge killed by Specs Regieleki being the main candidate. Trick room poses as a threat to the team as well, not to mention how there is almost nothing you can do against Glastrier. If you are seriously keen on running Weakness Policy Moltres, I suggest Ninetales-Alola w/ Sash which uses Ice Shard to provoke the weakness policy. The idea should be to protect Moltres turn 1, set up aurora veil with Ninetales, allow Glastrier to use max hailstorm into protected Moltres which activates weakness policy to sweep. However, as aforementioned, it's really hard to counter Dusclops + Glastrier unless Moltres is Life Orb which allows it to K.O 252HP 4sp.def Dusclops, and you have to hope that Glastrier is weakness policy, not Life Orb. Otherwise, you get Garaunteed K.O. However, with some investment in bulk, you can live Glastrier Max Hailstorm but you have to account for LO damage + Hail Damage.
I would really recommend Zapdos + Grimmsnarl here however, but if you genuinely want to stick to Moltres, then I suggest not leading with Moltres against Glastrier + Dusclops. Rotom Heat has always been known as a good counter to Glastrier:
252+ SpA Rotom-Heat Max Flare vs. 252 HP / 4 SpD Dynamax Glastrier: 206-246 (49.7 - 59.4%) -- 99.6% chance to 2HKO
And Nasty Plot set does a solid 93% to Dynamax Glastrier with Overheat as well. If you're struggling against Glastrier, without a doubt, use Rotom which I personally believe is a good counter. Urshifus work too, but they drop your defenses and allows you to be K.Od after hail damage.
Because of the dual typings Rotom-H and Regieleki, I would switch Rotom-H for Regieleki. Screens Eleki seems nice, but all it can really do is set up Reflect against Glastrier, only to be 2HKOd and trick room goes up. You also may want to try carry taunt on Fini as well, alongside Haze to provide optimal support. Calm Mind is nice, but Specs Eleki K.Os it anyways before it sets up, and Calm Mind won't help you against Kartana or Rillaboom anyways. But, if you think Calm Mind has been good for you so far, by all use it. Personally, I don't find it that great.
Instead of Life Orb Landorus, Landorus typically doesn't dynamax. I would recommend Scarf Landorus as it has great unison with Rotom-H (Levitate). This also allows you to run Life Orb Moltres if you wish, which I personally find interesting. Because of the fact that people typically think that Moltres has Weakness Policy, they sometimes tend to shy away from using super effective moves. However, scoring K.O on turn 1 on Dusclops with Life Orb Max Darkness can really surprise them.
And the newest idea I have just thought of is to use Ally switch Rotom, ally switch turn 1 and get off Max Darkness, Rotom lives and simply do as much as possible with Overheat + Max Guard, then max darkness into Glastrier and potentially picking up on K.O due to Sp.def drop.
That's a possibility:
Rotom-H w/ Nasty plot, overheat, thunderbolt, ally switch.
Moltres w/ Life orb.
Kartana w/ AV.
Landorus w/ Scarf.
Fini w/ Taunt + Haze in case Glastrier max quakes too much.
Because of no weakness Policy Moltres, Comfey = not great so I would recommend using Power Herb Nihilego as it is a huge offensive threat and can benefit from Airstream from Moltres, not to mention that it can deal 62-74% (Meteor Beam) to Glastrier. You could also just lead with Nihilego, draw in Max Quake, switch to Rotom-H and get off a free Max Darkness.
so Nihilego w/ Power Herb.
Alternative is to use something similar to this team:
https://pokepast.es/8cbaa4fc716839a2
Where Grimmsnarl can provide speed control with Tricking Full Incense, drop sp.atk with Spirit Break, taunt and fake tears which helps dmax Zapdos:
252+ Atk Life Orb Glastrier Max Hailstorm vs. 4 HP / 0 Def Dynamax Zapdos: 393-463 (118.3 - 139.4%) -- guaranteed OHKO
^^Max Guard turn 1, fake tears, then turn 2 switch to landorus, allows Zapdos to tank Max Hailstorm, Zapdos can target 2nd slot, Landorus finishes off with fast Earthquake. Or, you could just lead with Grimmsnarl + Nihilego, switch to Rotom-H turn 1, fake tears, then after a mon faints, late-game Dynamax Zapdos.
If you want to know some more counters to Glastrier, this guy has it all covered in this video:
https://www.youtube.com/watch?v=eNWVVE-THPk
Kartana could also serve as an alternative Dynamax option too.
I know I didn't really make myself clear, but if you have any further questions, by all means ask!
Hope I helped!
