[Vanilla] Ranged Unit VS Siege Unit: Which ones deal more damage against ships?

[Lonecat Nekophrodite]

Supposing that the two unit classes came from the same era and has the same attack. Comparing Ranged unit and siege units
1. At Level1, Which one deals more damage against ships?
2. When promoted with anti-ship promotions, Which one deals more damage against ships?

 

[Sostratus]

Ranged units have an inherent penalty of -17 vs ships. In other words they deal half damage. Siege units deal full damage. However, ranged units in any era have a ranged strength of X-5, if a melee unit would have strength X. Siege units, on the other hand, have a bombard attack of X. So the power gap is actually 22 if this scenario were possible (before the modern era where units get weird they never overlap.) In a more concrete scenario, bombards vs fields cannons against frigates, the gap is 12 as the field cannon is more advanced.
Combining volley and arrow storm gets you a +12 vs land and naval units, so your net penalty is only -5. Siege units only have the 3 tier promo Advanced Rangefinding, which gives +10 vs naval. So to summarize...

No Promotions

• "Same Era" : siege has +22 advantage
• Bombard/Field cannon: siege has +12 adv

One promotion

• "Same Era" : siege has +17 advantage
• Bombard/Field cannon: siege has +7 adv

Two promotions

• "Same Era" : siege has +10 advantage
• Bombard/Field cannon: siege and ranged are equal

Three+ promotions

• "Same Era" : siege has +20 advantage
• Bombard/Field cannon: siege has +10 adv