Well, this kind of necromancer should be able to kill, very slow, but kill, in hell. However you won't kill anything if in parties, the melee damage you would want to do with your weapon would be too low for hell's monsters, and the bone spear will be also too weak for hell's monsters. This build lacks one deciding point - the synergies for the bonespear aren't maxed as much as possible.
As a good example I can take my necromancer. He has the best items, true, but even without them he can kill decent and fast enough. All synergies for the bone spear are maxed, he summons only revives that serve him as a living shield while he's teleporting (Enigma armor), and he has an Iron Golem cast over
Kelpie Snare that slows even better than a Clay Golem with decent points put into skill does. Of course I have one point put into Skeleton Mastery for Revives and 1 point into Golem Mastery, both have in the end +24 (Skeleton Mastery) and +19 (Golem Mastery) to skills through the items and that is great enough for Hell. This Iron Golem has good life in hell + the life-giving shouts from Call to Arms so he survives pretty much anything Hell has to offer. And with the bonespear my necromancer is doing 5235-5528 damage + I use Corpse Explosion and this kills well and fast even in party of 7 additional people in Baalruns.
That's how a deadly Necromancer that can survive is skilled to be Hell-able. Good items are requirement, though.