Input I shall give to clarify the situation to you, Tharine.
What Mojang did for 1.6 that "broke" Vanilla PvP, was that they had both nerfed instant health potions by 33%, and Regeneration by 50%. Additionally, they had changed the crafting recipe for glistering melon, (ingredient needed to get health potions), by making it require 8 golden nuggets instead of 1. It seemed that they wanted to tone down all potions that healed the player, (they also changed the effect from golden apples by adding absorption). However, by doing this, they did not tone down the effect of strength, and instead, buffed it indirectly. What I mean by this is now swords provide information when hovering over them, with stats on how much damage you will be doing. (for diamond swords, +7 damage). This does not mean that the diamond sword does 7 damage, (3 and half hearts) as it did in 1.5, it simply means it adds +7 to the flat unarmed damage of 1 heart, (half a heart). Because of this, strength buffs that extra heart of damage from the fist, meaning that a diamond sword with strength now does more damage then it used to. (Causing people to believe that strength was buffed.
As IDANUB has brought up, we do not need to configure with the files that contain the damage formula, or anything remotely difficult as that, all we need to do is to either remove strength completely, and limit enchants to prot 3 sharp 2, OR, have the enchants and potions like the legacy at badlion. (Something like prot 4, sharp 4, strength limited to 1).
http://imgur.com/a/6KA6d#0 (Reddit post about sword damage buff)
http://www.minecraftwiki.net/wiki/Sword (In 1.6.2, instead of replacing the barehanded damage 1 () Swords now add their damage onto the barehanded damage, which results in all swords doing 1 () more damage than before.)
http://www.minecraftwiki.net/wiki/Version_history#1.6.1 (Regen, health potion nerf).