These are more than likely the best hands for BLU for Disseverment, Frenetic Rip, and Hysteric Barrage. There is a Huge DEX bonus over Alky's with about an equal -STR. Also, additional ACC to help with the multi-hits landing.
Alkys, you do want to use for vertical cleave and cannonball at least. The mittens though, are better for blu's multi hitting spells and melee if you don't have haste gloves like homam and such.
To the contrary, if you do the calculations you will see Enkidu Mittens are in fact only better for Hysteric Barrage, damage wise, compared to Alkyoneus' Bracelets.
All Spells, STR+1 = +0.25 base damage from fSTR
Hysteric, DEX+1 = +0.3
Frenetic, DEX+1 = +0.2, STR+1 provides an additional 0.2 so STR+1 = +0.45
Disseverment, DEX+1 = +0.2, STR+1 provides an additional 0.2 so STR+1 = +0.45
Of course, this assumes you have not capped fSTR, and that the STR provided by both is enough to tip fSTR over to the next digit (since fSTR does not take decimals into account).