Some of you who played classes that mained 1-handed weapons, such as rogues, may know that Replica Blood Guard's Cleaver, and the alliance counter-part, Replica Lion's Fang, were 2nd BiS in instanced PvP next to the unobtainable Sunstrider Axe. With 7.3 these lvl 1 epic weapons are now BiS in instanced PvP due to Sunstrider Axe being nerfed with the normalization of weapon speeds. But why is that exactly? The way scaling essentially works is that it takes into account for weapon speed and damage, but there is another factor. Rarity. Since the normalization of weapon speeds, the weapon speed factor is highly irrelevant now, since every dagger has the same speed, every sword, axe, mace has the same speed etc. That means rarity becomes the most important scaling factor at this point. The scaling of rarity goes by the same logic as one would assume. Orange>Purple>BoA>Blue>Green>White>Grey. Legendary obviously being the rarest of them all, so it scales the highest. This means that BiS weapons for level 60s are the obtainable legendaries for level 60s, and same logic for 70s. At a lower level (mainly 19 & 29), this means that the earlier mentioned replica weapons are bis, as well as the Miniature Winter Veil Tree when it comes to daggers, and Replica Staff of Guldan in terms of 2-handers. Thanks to @Bubbie and @Outplayed for discussions on the topic, as well as in-game tests. The initial find/idea was sparked by @Bubbie to my knowledge and @Outplayed had similar theories.