Let me first qualify that the Schools in DnD are dumb and the placement of many spells makes little sense (hence I play very few magic users, and my Gnome alchemist is only a scorcerer so he can effectively blow things up)
with that said I'd change the Necromancy designator to something like 'Somatic manipulation' and then allow it to effect the generation, growth, decay and destruction of living matter and 'life energy'
A Necromancer deals with the 'negative' aspects of this (decay and destruction)
A Vitimancer with the 'positive' aspects (generation and growth)
*an evil Vitimancer might have created the Owlbear and other abberant creatures
a lot of Druid spells could fit in the the Somatic School too