It's been over a year since the last update to Fellowship NPCs. Part of the argument against making them too good before was that FFXI is a party-based game, and they don't want to encourage soloing too much. However, given the ability to use Campaign as a viable replacement for (mediocre) exp parties, I think it's time there were some updates to the NPC system.
1) Allow party-only buffs/spells to be cast on them.
They take up a slot in your party already, so why not? Furthermore, it seems somewhat silly and arbitrary that a RDM can cure their NPC, but a BLU or DNC cannot.
2) Increased tiers of shield/healer/attacker.
I'd like to see a third tier of shield/healer/attacker. The third tier of shield should attempt to maintain hate on his engaged target at all times (instead of simply trying to keep it off of you). The third tier of healer should cast only healing and enhancing spells; no more wasted MP on resisted enfeebles (or successfully silenced crabs). Furthermore, it should use Regen and be a bit more intelligent on MP usage (I don't need Cure V the moment my HP hits yellow). TBH, second tier attacker is pretty much fine as is, but I wouldn't mind seeing something like an Attack/Accuracy/Store TP trait tossed on top.
3) Remove exp penalty.
Given the BST changes, it makes no sense for NPCs to cause an exp penalty any longer. The limited availability of Tactics Pearls (and limited number of kills per cast) is a self-moderating failsafe to prevent any sort of NPC exp abuse.
4) Allow NPCs in level-capped zones.
The level-capped areas are, by-and-large, devoid of life round-the-clock; there's no reason to dis-incentivize people from going there. If my NPC can make it to Misareaux, he can make it to Riverne or Sacrarium.
5) Unlock limit break 4 and 5 for NPC.
We've been stuck at 65 for years. This is long overdue.
XI Wiki

