Slow at the second level isn't needed by anyone playing SoD. But a convenient interface—now that's a different story!
As an off-line player, I'll say that even it stresses me out to drag artifacts and troops back and forth through hero chains, especially if, for example, you need to transfer from a hero who has 30 flies to one who has only one! (And having to hold Shift on top of that)... I can imagine how hard it is for online players, especially if the time limit is 1-2 minutes :-)
Although in off-line I'll have to play SoD, because in TE, definitely no one will be playing off-line... :-(