Paradox games have huge amount of DLCs, if you buy them all together at a later date it could feel very overwhelming, but if you buy them as they come out and think about the number of hours and new content they are adding you see it is actually not that expensive. Most importantly every DLC comes with a considerably big FLC that adds new mechanics to the game.
I think CA should use a similar model, release smaller, cheaper 1 LL, few units DLC packs for some faction with missing units and inferior mechanics. And add that faction new mechanics for free with the DLC money. As an example: say give Empire new mechanics or update their mechanics considerably, but also release a Knightly Orders DLC that adds 2-3 new units and a single LL starting in the New World. People who do not buy the DLC will not have access to few units but will get access to the new and improved Empire faction for free.
Similarly, a tiny DLC adding Neferata as a starting LL at the different position for the Vampires could come with free updated tech tree and mechanics to Vampires and so on for other core factions.
For DLC faction bundle the content in a pack as an example: add Ghorgon and a new LL for Beastmen, 1 unit and Lord to Chaos, 1 LL and unit to Wood Elves, and possibly one more Bretonnia LL into a pack. But do change the horde mechanics for free, give Wood Elves new tech tree for free and improve their mechanics, and improve Bretonnia mechanics wise as well . So, this way shiny new units are the DLC, mechanics are free for all.
These DLCs should even cost less than QnC, since the content would be less. Or cost the same price if they are adding similar amount of content.
Hopefully this will also be an incentive for CA to release Patches more regularly as well, with the release of each new DLC/FLC.
What is funny that we must be the only Community on Internet who actually asks for more DLCs. But CA just refuses it. Just look at the steam score of ToB or better looks at the difference in upvotes for any article relating to Warhammer compared to 3K in reddit. Warhammer is the golden egg laying goose.