WITH HYPER BEAM AND 43+ HP ON BOTH:
Carvanha/Houndour
1: Slash Carvanha+Return Houndour
2: Hyper Beam Nuzleaf+Return Murkrow
3: (Recharge)+Protect
4: Hyper Beam+Return Murkrow

Carvanha/Nuzleaf
1: Hyper Beam Nuzleaf+Return Carvanha
2: (Recharge)+Return Houndour
3: Surf+Protect
4: Surf+Return Murkrow

Houndour/Nuzleaf
1: Hyper Beam Nuzleaf+Return Houndour
2: (Recharge)+Return Carvanha
3: Surf+Protect
4: Surf+Return Murkrow

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OTHERWISE (aka old strats):

Carvanha/Houndour
IF IN TORRENT AND NEED SLASH DAMAGE:
1: Slash Carvanha+Protect
2: Surf+Return Houndour
3: Surf+Return Murkrow
IF DEAD TO HOUNDOUR:
1: Surf+Return Carvanha
2: Protect+Return Murkrow
3: Surf+Return Murkrow
OTHERWISE:
1: Slash+Return Carvanha
2: Surf+Return Nuzleaf
3: Surf+Return Murkrow (range)

Carvanha/Nuzleaf
1: Slash Carvanha+Return Nuzleaf (flip if don't want Slash damage)
2: Surf+Return Nuzleaf
3: Surf+Return Murkrow (possible range)

Houndour/Nuzleaf
IF IN TORRENT AND NEED SLASH DAMAGE:
1: Slash Nuzleaf+Return Houndour
2: Slash Carvanha+Return Nuzleaf
3: Protect+Return Murkrow
4: Surf+Return Murkrow
IF DEAD TO HOUNDOUR:
1: Slash Nuzleaf+Return Houndour (Surf with L39 and average/bad stats)
2: Surf+Return Carvanha
3: Surf+Return Murkrow
OTHERWISE:
1: Slash+Return Nuzleaf
2: Surf+Return Carvanha
3: Surf+Return Murkrow (range)