Well, I think that Shroomish outclasses Treecko, so I would switch to Shroomish. Using Mew's set here.
Shroomish (F) @ Toxic Orb
Trait: Poison Heal
EVs: 76 HP / 196 Atk / 236 Spd
Jolly Nature (+Spd, -SAtk)
- Spore
- Swords Dance
- Seed Bomb
- Drain Punch
Outclassing Mankey is Mienfoo.
Kojofuu (M) @ Life Orb
Trait: Regeneration
EVs: 236 Atk / 36 Def / 236 Spd
Jolly Nature (+Spd, -SAtk)
- Drain Punch
- Fake Out
- U-turn
- Stone Edge
I'd be interested to see how a Magnemite works on your team. I think it might help a lot. Let's replace Growlithe for it.
Magnemite @ Evolution Stone
Trait: Analyze
EVs: 236 HP / 36 Def / 236 SAtk
Quiet Nature (+SAtk, -Spd)
- Flash Cannon
- Thunderbolt
- Substitute
- Hidden Power [Ice]
Murkrow I would suggest moving fully towards the physical side, then adding some nice Thunder Wave support to take down Scarfers and Dragon Dancers. Plus Roost for healing.
Murkrow (M) @ Evolution Stone
Trait: Mischievous Heart
EVs: 116 HP / 156 Atk / 20 Def / 20 SDef / 188 Spd
Jolly Nature (+Spd, -SAtk)
- Sucker Punch
- Brave Bird
- Thunder Wave
- Roost
Instead of Swinub, I would suggest Phanphy, who is bulkier and a better lead (make it your lead.)
Phanpy (M) @ Evolution Stone
Trait: Pickup
EVs: 196 HP / 196 Atk / 116 Def
Adamant Nature (+Atk, -SAtk)
- Earthquake
- Stealth Rock
- Ice Shard
- Seed Bomb
Ralts has awful stats. How about replacing it with a Woobat?
Koromori (M) @ Evolution Stone
Trait: Simple
EVs: 76 HP / 12 Def / 236 SAtk / 180 Spd
Timid Nature (+Spd, -Atk)
- Assist Power
- Calm Mind
- Charge Beam
- Air Slash