Here's a list from 2002 of what lands and what doesn't land. I remember not being able to land shit on Trakanon and basically any Kunark/Velious era monster for a long time. I believe Verant addressed Necros not landing shit during the Late Velious/early Luclin era.
http://web.archive.org/web/200212210...?TOPIC_ID=9151
In general, Necros are insanely weak during the Kunark/Velious era. This was intended, as everyone cried about Necros being overpowered during classic, and Verant responded by making Necros complete garbage during the proceeding expansions. They of course went overboard, but this is Verant we're talking about. They're not very good at gameplay balance.
Only when dot stacking was implemented and the cap on how many spells could land on a mob was increased did things get better for Necromancers during raids. There were other changes as well -- nukes not having the skeleton illusion, pets being unfearable, etc etc etc.