I am a total war vet, so its hard for me to tell how accessible the game really is, I might take things I know for granted. That being said there are several places where more information is the hands of the player would be useful.
1. Agent abilities and descriptions: The current way to figure out what agent does what is very clunky and involves going into the encyclopedia and browsing every ability individually. This is easier if you have the agent, a skill tree should be available to browse in the encyclopedia to give the player an overview of what the agent can be built into. A short description of what agents do best at on the campaign map would also help (the battle roles are already listed). A Banshee is a great assassin for example, but I found that out by going through every campaign skill on every VC hero (as well as browsing the tech tree).
2. Spell damage information: What do damage spells do? It seems only the wizards know for sure. At least for me personally, then magic has been about casting spells and hoping that they do well, rather then knowing what the impact will be. Buff and debuff spells are the exception and much easier to understand and use from the interface.
3. The army cult of secrecy: If there are hidden modifiers, then please list them. Previous games have had things like a hidden +10 against cavalry. If units in Warhammer have similar anti large bonuses, please tell us by listing it on the unit card. The available statistics in game should inform the player and not mislead them into thinking that units match up differently then they do. If this is not the case this time around, then it can be stricken off the list.
This is a venom free post, the game is already great, I just think that these modifications would make it even better.