There have been a few games where you could either acquire/hire an NPC that would battle for you in PvE & PvP. UO(Anywhere, but they kinda svcked), SWTOR(Open world only), & DAOC (Minstrels could charm NPCs to fight for them anywhere.) Other games I'm sure...

Skyrim allowed you to have a companion and other followers dogs etc. Sadly most MMOs would not allow you to take your companion into PvP or into instanced dungeons. IMO this makes sense for their systems. They just built their systems WRONG! ~

So here is how I propose you can have a companion in TESO in PvE and PvP. You make them like D&D Cohorts. You dont simply Hire/Acquire them for free. It can be based off of Speechcraft Or an entirely new tree (Leadership or Warlord) or a combination of say Speech/Leadership trees.

With skill examples like

40 Speechcraft [Leader] NPCs up to lvl 27 will fight for you as a companion.
60 Speechcraft [Commander] NPCs up to lvl 37 will fight for you as a companion.
80 Speechcraft [Influential] NPCs up to lvl 43 will fight for you as a companion.
100 Speechcraft [Renowned] NPCs up to lvl 50 will fight for you as a companion.

Bonus fusion skills in other trees:

60 Sneak [Wing Man] Your companion distracts shopkeepers and guards.

80 Smithing [Brilliance] Your companions devotion to you shows in the shiny nature of your armor +15 Fortify Heavy armor.

70 Alchemy [Savory Servant] Your companion taste tests all ingredients to keep you safe from harm. +10 Fortify Alchemy.

And so on...

I'd just like to see a system where you really do have a cohort/companion and not a PET! I think Skyrim did a good job with the companions. I'd just enjoy seeing them in TESO as well but as I explained more Dungeons and Dragons like where you need skills to have them. I think that would work out.

Personally, I dont like the idea of lugguing around a companion. Again its a personal thing, but I like the lone adventurer type of game.

Also can you imagine in PvP having 200 people on your screen AND 200 companions. lol.
Same thing with instances and Raids.

Meh, don't think it'll work too well in this game.
What happens when more than one person has the same companion? There can only be one Lydia.
Can't see it happening, really.

I can imagine it its called Conjuration: Zombies/Thralls/Atronachs/Daedras every where...

You would need 100 Speechcraft for what I'm proposing, all those 200 raiders would NOT have 100 Speech.

I'm just proposing a way to have a companion and not be a Necromacer type of character and use a skill thats lets face it pretty pointless for the most part, even in a game like Skyrim.