The "Electrical Engineer" is powerful for vanilla however the bot summons have been increased from one to three (I forgot if this can be gained at early or max level). The Bot summons have been edited to deal electric damage and they do benefit from the electric passive power boosts.
Finally if you desire a mixed gunner, buffer, "Summoner" that actually uses the vanilla skills with optional summon boosting mods then this is an interesting option:
So while I haven't played or seen anything on the TL2 Workshop that is truly the Necromancer from D2... it does seem that at least Darkthan was able to mimic that theme and there are plenty of decent alternative options linked above.
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Also be aware that classes from two mods that share the same name: Darkthan's "Druid" and Drew's "Druid" would override the other if placed above in the mod load order.