WM LOB

Wave Master - Stun/Flank
Valkyrie - Damage/Flank
Swordsman - Damage/Flank
Giant Skeleton - Tank
Mini Pekka - Mini-Tank/Support
Musketeer - Crowd Control

Upgrade Priority
Valkyrie 1>2>3
Swordsman 3>2>1
Giant Skeleton 1>3>2
Mini Pekka 2/1>3
Musketeer 2>1/3

Matchups
Barbarian King 70/30
Archer Queen 70/30
Monk 30/70
Shield Maiden 60/40
Wave Master 50/50
Countess 60/40
Skeleton King 30/70
Royal Champion 50/50

Wave Master's 3rd ability lets you lob either Valkyrie or Swordsman to the other side of the arena. In most cases, swordsman picks up more value than valkyrie, but against healing decks, Valkyrie is much preferred for her 3rd star ability. Always play your wave master and valkyrie/swordsman combo on either the middle or mid left or mid right lane.

Giant Skeleton is used against the enemy's damage dealers. You can to upgrade his 1st star in most scenarios. The Mini pekka's dissipate is very useful in situations where the enemy has a lot of minis that require energy. The Musketeer is very strong against slow troops melees.

Against enemy flanks, you want to play it to your advantage and maximizing the use of both of your damage dealers, swordsman and valkyrie. While one of them can be lobbed to the other side of the arena, one of them can be used to catch the flanker.

Do not use war toot unless your enemy has a very heavy stun deck. Using war toot will disable your Wave Master's 3rd star ability. The wave master will not lob your mini to the other side of the board. Use the war toot only when the enemy has a crazy amount of stuns, for example a full stun deck with mega knight, electro wizard and ice wizard.

Pancaker can heal your troops that are being lobbed to the other side of the arena to give them more survivability to deal more damage and give off more value.