In Pokemon Go, Dragonite is a precious Pokemon because it is dragon-type Pokmeon. There are only 1st generation Pokemon, so no steel- or fairy- type Pokemon is in Pokemon GO. That means there is only ice-type Pokemon which has type effectiveness against to dragon-type Pokemon.
Additionally, Dragonite has higher CP compared with other species and is expected as the most powerful Pokemon.
Slowbro is a Pokemon which water-type moves are not effective against to and which can use psychic-type moves getting its power increased due to STAB.
Compared with Alakazam, another psychic-type Pokemon, Slowbro has higher CP. Therefore, its charge move, Psychic, can damage rival Pokemon much. Additionally, Psychic is super effective against to poison- and fighting- type Pokemon.
Lapras has higher CP relative to other ice-type species. It has excellent stats and can use powerful ice-type moves with STAB. Therefore, Lapras is one of the best Pokemon for fighting against to Dragonite.
For fast move, Ice Shard is better than Frost Breath based on DPS. For charge move, Blizzard is the best.
Venusaur have higher CP and can use grass-type moves, which are super effective against to powerful water-type Pokemon represented by Vaporen. For fast move, Vine Whip is better than Razor Leaf based on DPS. For charge move, Solar Beam is the best due to higher power and DPS.
Charizard have multiple tipes, fire and flying, and so ground-type move is not super effective against to Charizard. For fast move, Wing Attack has higher DPS than Ember. For charge move, Fire Blast is recommended.
There are a few steel-type Pokemon which fire-type moves are supper effective against to. However, Charizard can fight against to grass- or bug- type Pokemon very well.
Balstois can use Water Gun, the fast move famous for its higher DPS, and increase the power of the move by STAB. Even though Hydro Pump is recommended for a charge move, it cal learn other charge moves, such as Flash Cannon and Ice Beam.
Although Golem have ground- and rock- type, which have many weaknesses, but can learn moves work very well. Mud Shot is a higher DPS move along with the other fast moves. Stone Edge, a rock-type charge move, is super effective against to flying-type Pokemon which use flying-type moves super effective against to Golem.