I dont particularly have any attachment for Zoro vs Admiral even tho I would like to see a conclusion to the unfinished business Zoro and Kizaru have from Sabaody which also fits thematically for Dark, King of Hell, representative of Asura and Light, representative of Devas.
It always seemed weird if all Admirals fall to a single crew so I dont mind Zoro not fighting one despite him being the best fit for it. However, Law and Kidd dont seem like someone who will ever be capable of taking down an Admiral in 1vs1, unless they team up again.
I would like representatives of different factions to take on Admirals. For example, Zoro the SHs representative takes one Admiral, Wyper the Old Kingdom representative takes on another one, Weevil the Shichibukai representative takes another, Sabo the Revolutionary representative takes on Akainu. In that case, Law and Kidd would take on Gorosei each, Sanji too. Yamato/Cavendish another Gorosei, Crocodile the last Gorosei match-up. Luffy and Momo go chasing after Imu.
If there is greater narrative weight in Zoro vs Gandhi, I would take it instead of Zoro vs Kizaru.
And I also think, Zoro will have at least 3 fights in final war so I dont mind if one of those aint vs an Admiral.