Disclaimer: Kind of went off tracks multiple times regarding the actual missions/NPC Agents relation to the current lore there but it’s now written, so be as it is. As someone stated already, missions need a massive update. As PVE in general should have. But that’s a discussion for another topic.
To understand the story & lore one needs to read a lot about it to catch up. Eve is an old game and the story sort of has evolved within the past 20 years. The game also tends to be one of those ‘played in the long run’ deals. Take the current story arc for example, it has been going on for half a year now - you could also argue that the current story arc has been going on for 15 years when the Drifters were first introduced.
Don’t get me wrong - i’m not saying this in a accusing bad manner - but for me this seems like you haven’t educated yourself with the backstory of New-Eden and latest news. The game actually has a very vivid and story rich world when you take the initial deep dive to it. Getting to know the backstory is very essential to understanding the relationship between Triglavians, Deathless and Drifters.
I would start from the beginning of the story of New Eden and pay special attention to Jove Empire. Jove, Deathless, Drifters, Sleepers, Zarzakh, The Fulcrum, The Warden, Wormholes, Upwell Consortium are all tied together and connect. Additionally i would read about clones and cloning technology because it’s sort of on the surface currently with Vanguard and e.g. Breacher Pods and Upwell Consortium.
For the delivery aspect of story/lore though? It can be a bit shrouded in mysteries until it all comes together. And a lot of the stuff is sort of left for the players to decide. Or just for the player to connect the dots. Often times it’s a bit spread around all over the place, which, let’s admit it, isn’t optimal at times… But it’s also something that automatically happens when the content simply becomes so huge that it’s hard to put on one place. Players occasionally try this though for e.g. regarding Triglavians: [Compilation] The Lore of the Triglavian Collective
Let’s use Deathless ship hulls as example: We know that their ships use Caldari & Minmatar technology right? So maybe it’s not more or less grandiose than that. Deathless has engineers and researchers working for them from both factions and thus they came out with the hull design and simply it’s branded as theirs.
But there is more to the ships than just ‘cool drawing from design department’ - let’s take e.g. Breacher Pods that came with the Deathless Hulls:
Now this article has a lot information on it doesn’t it? 
Here’s the source: https://universe.eveonline.com/new-eden-news/the-warden-revealed-as-upwell-condmen-deathless
Links for resources.
I know it’s a lot of reading.
But it’s a lot of lore & story too!
OH! And one thing that is often overlooked is simply right clicking → Show info → Description. There is a lot of cool stuff all over the place when you start digging. Like visit sightseeing beacons in space. There is so much story written in those places!