Now that Lv 1000 has posted unofficial infosubs for the Necromancer Cavalry Lances in the infosub forum, and it's been confirmed that their effect is just a flat +7.5% damage boost when using a rider armor, I'm going to go ahead and repeat something I said earlier in this thread:
The lances should probably be buffed, or at least have their effect slightly altered, so that they boost spell damage instead of weapon damage.
These Necromancer Lances are clearly meant to compliment the aesthetics of the Necromancer Cavalry armors, which makes it somewhat weird that the all of the lance weapons 100% anti-synergistic with the armors that they match. Because all of the Necromancer Cavalry armors are either defensive or spellcaster lean, there's effectively no benefit to using any of the Necromancer Cavalry Lance weapons with any of them, since you will always deal greater damage with a 100-proc weapon even factoring in the damage boost from the lance MCs.
Granted, this is an ultimately very minor complaint about an item few people are likely to use anyway, but I think it is worth bringing up here again.