Other than hitting Ferrothorn harder, Superpower is kinda useless on Crawdaunt, as its main STABs are rather high-powered. Swords Dance is used over it to give it more power, and a +2 (neutral) Knock Off can do this to Ferrothorn:
+2 252 Atk Adaptability Crawdaunt Knock Off (97.5 BP) vs. 252 HP / 88+ Def Ferrothorn: 268-316 (76.1 - 89.7%) -- guaranteed 2HKO after Leftovers recovery
A neutral Leaf Storm hits Therian Landorus harder than a 2x super effective Hidden Power Water. Fire is the preferred Hidden Power type on Serperior so it isn't walled hopelessly by Steels. HP Water is useless in this regard as it only hits them neutrally and even Leaf Storm still outdamages it against them.:
252 SpA Life Orb Serperior Leaf Storm vs. 252 HP / 8 SpD Landorus-T: 230-270 (60.2 - 70.6%) -- guaranteed 2HKO after Leftovers recovery
252 SpA Life Orb Serperior Hidden Power Water vs. 252 HP / 8 SpD Landorus-T: 143-169 (37.4 - 44.2%) -- guaranteed 3HKO after Leftovers recovery
Specially defensive Talonflame is preferred over the physically defensive variant, as:
-Talonflame is boosting its Defense with Bulk Up anyway
-it gives Talonflame an easier time against Charizard Y (it happens to resist all its main attacks), special Mega Altaria, and Heatran lacking Stone Edge/Ancient Power.
The fully offensive Talonflame set (max Attack/max Speed) makes better use out of Flare Blitz, IMO. The bulky variants can afford to forgo it, as Talonflame can even use Steels as setup bait, and can shut defensive ones down with Taunt or Will-o-Wisp. You could use Flare Blitz, though, but you lose out on that extra bit of utility:
-Swords Dance
-Brave Bird/Acrobatics
-Taunt/Will-o-Wisp
-Roost
Nature: Adamant
EVs: 248 HP/252 Atk/8 Spe
Item: Leftovers/none
Ability: Gale Wings
or
-Brave Bird/Acrobatics
-Bulk Up/Taunt
-Will-o-Wisp/Taunt
-Roost
Nature: Careful
EVs: 248 HP/252 SDef/8 Spe
Item: Leftovers/none
Ability: Gale Wings
This is what Charizard Y can do back against Talonflame:
252 SpA Mega Charizard Y Fire Blast vs. 248 HP / 252+ SpD Talonflame in Sun: 143-168 (39.8 - 46.7%) -- guaranteed 3HKO after Leftovers recovery
252 SpA Mega Charizard Y Solar Beam vs. 248 HP / 252+ SpD Talonflame: 34-40 (9.4 - 11.1%) -- possibly the worst move ever
252 SpA Mega Charizard Y Focus Blast vs. 248 HP / 252+ SpD Talonflame: 69-81 (19.2 - 22.5%) -- possible 6HKO after Leftovers recovery
This team appears to be an offensive team, and Chansey is dead weight on those teams, due to its passiveness. It fits best on stall teams. You need Stealth Rock on this team, as it's a very important entry hazard. Crawdaunt is rather frail, which means it can't really get into battle by itself safely. U-turn support is the best way to get Crawdaunt on the field. Jirachi happens to provide both of these things:
-Stealth Rock
-Iron Head
-U-turn
-Fire Punch/Body Slam/Thunder Wave
Nature: Careful
EVs: 252 HP/176 SDef/80 Spe
Item: Leftovers
What's the point of Excadrill having an Impish nature when you're not even investing in its Defense? A better take on bulky spinner Excadrill, IMO, is this set here:
-Earthquake
-Iron Head
-Rapid Spin
-Toxic/Stealth Rock
Nature: Careful
EVs: 252 HP/4 Def/252 SDef
Item: Leftovers
Ability: Mold Breaker