Can all players utilize DLC content in custom battles/Mortal Empires if only one player has it?

If, say, the host of a custom multiplayer battle or a Mortal Empires campaign owns every single DLC in the game, will it be shared to other players in that match, even if they don't own it themselves?

I would like to play the Mortal Empires campaign Total War: Warhammer II with a friend of mine as they are going to be getting the game soon, but they do not own the first game nor will they have anything but the vanilla game. I'm hoping that since I own everything, the content will be shared.

Solution 1:

NOTE: I added some extra info in the first paragraph for future people that come looking with a slightly different question, hoping that this answer will suffice.

As it is done in the first game with Co-op. You can play whatever you want. The other player will be able to see it, but not play it. So lets say, you pick wood elves. You have every feature (pre-norsca) to play with. He can see your armies, spectate and fight with/against you. But he cannot play as the wood elves. For that he needs to own that content.

For your specific case, no you cannot play together. Mortal Empires is installed, but is only accessible for those that own BOTH games (this can be with no DLC). However that will mean that the scenario above goes in effect.