Except Skarbrand has two axes and daemons can't truly die.
And it doesn't look like this kit makes him. Also, to quote -
Skarbrand leads a vast army of daemons to Naggaroth and intecepts Malekith on a trip to see his Mother, he was then killed by Malekith when their forces met and his army defeated.
Still a headscratcher that the kit doesn't make Skarbrand, but this might be an explanation as to why.