I made these charts to help me decide which class to use based on their damage output. This does not consider important support skills like healing or buffs, so you must consider that for each battle. These numbers are per-turn damage output percentages. Each bird has different base attack, so for example Red doing a 100% damage attack will do less damage than Blues doing a 100% damage attack. For degen classes, these charts only track their per-turn damage and does not consider the following two turns' worth of degen.
Red:
Although Avenger is capable of dealing the highest single-hit damage, Red needs to be under 37.5% health to do the most damage. Stone Guard will do the next highest damage provided you have a source of statuses. Samurai does the highest unconditional damage with three chances to trigger weapon bonuses, meaning that the Dragon Breath and Grand Slam sets have three chances per attack to roll weapon bonuses. However, Samurai will miss Ironclad pigs without Bomb's damage buff or Skulkers' armor breaker. Paladin will do the highest single-hit damage and works great with the Protector's Aura set. Ronin/Knight and Guardian are rarely worth using.
Chuck:
If you got the Archmage upgrade, it outdamages Wizard with 4 or more foes; however, once you start chipping foes away, Wizard shines on 3 or less foes. Otherwise, there's no reason to use another class than Wizard, especially when given the Twin Lightning set. Mage, Rainbird, and Thunderbird work well with multiple teams, except Lightning Bird which requires specific teams to work effectively.
Matilda:
Druid is great for its damage & healing and is generally the best choice in all game modes especially with the Sweet set; however, it will miss Ironclad and Immune pigs. Bard does the most damage, which is amplified further with the Nightmare set, but has arguably Matilda's worst heal. Princess does respectable damage and healing, but needs support from other birds to adapt to setting aggro; I would only use it in Chronicle Caves with Red, or in arena when it's the daily objective. Cleric/Moon Priestess does low damage, but its support is great against foes with AoE, and pairs well with Thunderbird to smash AoE foes. Priest is difficult to use and I would strongly advise against using it, but pairs well with Marksmen if you must use Priest.
Bomb:
Contrary to popular belief, Berserker will do more damage in the long run than Sea Dog. Both have inconsistent damage, but if you have the "No Rage Chili" daily objective, there's no reason to not pick Berserker. Sea Dog will need heal support from Matilda to maintain its high damage. If you got the Corsair upgrade, it's generally the best class to use for consistent high damage; otherwise, Pirate is still a solid class to use due to its damage buff. Cannoneer and Capt'n have low damage, and you should only use them if you need the support skill. Use Cannoneer with Marksmen to spike single targets. Use Capt'n if you need its damage buff.
Blues:
Like Wizard, if you need pure damage, there's no reason to not use Spies. However, Blues have great support in all their classes, so you must consider the upcoming battle when selecting a class. Rogues does very high per-turn damage, but will miss Ironclad and Immune foes. Skulkers actually does more damage than Tricksters after a turn to set up armor breaker, and comes with a great support skill. Tricksters is great as a "hazer" (Pokemon term) in PvE, but you have better options in PvP. Marksmen requires a very specific team to function properly, which is limited to Samurai, Stone Guard, Lightning Bird, Priest, and Cannoneer.
