They're not weaker. Its just the fact that theres a bigger jump of attack from Crescent Moon and Death Crown. Either that or maybe the Wiki was wrong.
Edit: Old thread is old o_o
They aren't weaker. Vindictusdb/"the wiki" has the wrong stats on the 40 and 44 scythes. The game's weapons went through a giant stat overhaul and the Vindictusdb/"the wiki" does not reflect those changes for unreleased weapons in our version. Why are the lv40 and lv44 scythes weaker than this lv36 scythe?????