Why longswords have 0.225 lethality?

[seienchin]

I think it just represents that the longswords were quite lethal, usually swung with great power and thus able to shatter shields and cause damage through helmets and armour. Most of the units that use longswords lack armour (defence rating), aren't usually particularly disciplined and - unless their initially lethal attacks break the enemy will pretty rapidly lose morale.

Wait.... Isnt that what the general advisor tells you in Vanilla? ^^
I am not sure about rapidly loosing moral.
Anyway, many longswords (esspecialy the celtic ones) found from EBs timeframe were of a poor qualitiy, still its true that they were often swung from above, so had quite an impact. Anyway, roman shortsword were extremly deadly esspecialy in combination with their shield so I am sure romans were deadlier warriors than celts, but besider that:
Gladius has AP in EB, which makes it exremly good against armoured enemies and Longswords with hight lethatlity are good against unarmoured troops. This might not be accurate, but it balances the system.

@Burebist
Interesting... Adopting the Spatha because of the late roman lack of discipline... Any proof?