I though I would share a core I came up with that has insane versatility in it´s sets and even in which Pokémon you decide to use, revolving around Gligar specifically. Any of these sets and cores can be used for Bulky Offense and Balance alike. Also I listed a few other viable options in their sets, which can be used or not depending on what your team needs. So Gligar, Blastoise and Miltank. This 3 have very nice synergy between them and it´s a pretty simple core to fit in a team.
Gligar checks/counters pretty much all Fighting Types in the tier as well as a bunch of other physical attackers. Acrobatics gives it a way to hit Fighting Types. This move also powers up if the user doesn´t have an item which is pretty clutch considering Knock Off is a move that is quite prevalent in the tier. U-turn on it´s own is an insane move on Gligar as it allows it to pivot into your frailer Pokémon completely safe. Roost gives Gligar reliable recovery which is always great to have. The last move can change depending on your team.
Blastoise covers Gligar´s only 2 weaknesess, Ice and Water, and it´s a nice defensive Pokémon in general. Scald as your main STAB which also has a chance to burn, and Rapid Spin as form of hazard control for the team. The last 2 moves are up to what you want to run. To be honest Blastoise is a Pokémon that only needs Scald and Rapid Spin to do well, which gives it a lot of freedom for it´s last 2 moves.
Miltank is a fantastic Pokémon in my opinion and I can´t understand why isn´t used that much. While it has very good offensive capabilities, as a defensive Pokémon is even better. Both Sap Sipper and Thick Fat make Miltank really hard to take down, as they give it an inmunity and 2 resistances respectively, allowing Miltank to switch into a lot of Pokémon, both offensive and defensive alike, on top of being a Normal Type, which means it only has 1 weakness in Fighting, which Gligar does cover. It also has acces to reliable recovery in Milk Drink and can be a cleric thanks to Heal Bell, both which drastically increase it´s longevity. It even has acces to Stealth Rock should the team need it. And just like Blastoise, Miltank´s last 2 moves are completely up to you to choose what you want to run.
This core has 3 different variants:
A) Gligar + Blastoise + Miltank: This variant includes all 3 Pokémon from above, and it´s more suited to Balanced teams given the defensive backbone it provides. Blastoise would become the hazard remover for the team, then either Gligar and Miltank can be the hazard setter. In this variant, Miltank should be used with Sap Sipper as it´s ability, as the resistances to Ice and Fire provided by Thick Fat are already covered by Blastoise. Partners for this variant would include Dark, Fire and Fighting Types that could deal with opposing Steel, Dark and Ground Types.
B) Gligar + Blastoise: This variant would fit better in Bulky Offense teams. It uses Blastoise as the hazard remover, and Gligar can be the hazard setter or not should your team have one already. Also this variant goes really well with hazard stacking teams as it utilizes Rapid Spin as it´s form of hazard control. This variant appreciates Pokémon that can eliminate Grass Types. Normal Types, as they have good synergy with Gligar and can hit Grass Types with powerful neutral STAB moves, and Fire Types are a good option, oh and Ice Types as well.
C) Gligar + Miltank: The last variant. This one in particular would fit well in both Balance and Bulky Offense. Both members can be the hazard setter. Should your team struggle with opposing hazards, Gligar can run Defog. Also depending on the rest of the team, Miltank can run either Sap Sipper or Thick Fat whichever works better. Depending on which ability you choose for Miltank, Fire, Water and/or Psychic Types that can get rid of opposing Fighting, Ice, Fire and Grass Types respectively go well with this variant.