My Reavers are screen / Bloodtithe only.
Bloodwarriors very much depends on the opponent. Played a DoK last weekend. He had 2x30 WitchAelves, charged 1 group with Bloodletters and 1 with Bloodwarriors and got to damage both units due to striking after dying. Bloodwarriors need to be 10 to give leader the special weapon and then they tend to take out some stuff pretty good. Depending on opponent they might join Reavers as screen.