Thank you for the feedback. The formula is as Miacis answered. (Thanks for answering on my behalf!)
From me, I will explain the intent of the design.
For attack power, only half of the Stat is added
Instead, the might of the weapon is set higher, and its ratio to the damage deal is greater.
This changes are to solve the problem of many players who preferred to use only iron weapons even in later games. (I think this problem detracted from the fun of taking weapons from enemies.) When fighting stronger enemies, you now have to use stronger weapons to do damage.
And it is important to use different weapons depending on the situation, as most classes have class type(s) and are subject to one of the weapon effectiveness. The weapon effectiveness adds a fixed value bonus of +20 to Attack power and +30 to hit. (Fixed values are used because if the weapon’s might is large, tripling it will result in instant death damage.)
Half of Skl is added to AS
Since the worth of Skl was significantly low, I changed to make players want to raise their Skl.
By increasing Skl, armored knights, who are not as fast, and ballisticians, who are equipped the heavy weapon, can also increase their AS. (The addition of AS due to Skl is not affected by the weight of the weapon.)
I knew these would confuse players, but I preferred to balance them as one game rather than follow the FE grammar.