Sub-R {PvP} Weapon Passive

hi, i have an S80 {PvP} weapon that gives me the passive skill
"Special Ability: PvP Damage Lv. 1 - Inflicts additional damage during PvP."

and i have a Top A {PvP} weapon that gives me the passive skill
"Special Ability: PvP Damage Lv. 3 - Inflicts additional damage during PvP."

can someone please tell me why i am getting Lv. 3 on the A and Lv. 1 on the S80? And as i have researched from previous articles, it seems the bonus from the s80 is actually 5%. So how much am i getting from the Lv. 3 Top A weapon? Or is the Lv. of this passive not indicative of the magnitude of the PvP bonus?

thanks.

Sub-R {PvP} Weapon Passive