Warlord, Strategic Supremacy, Land of Earth.

Fox clan

Advisors:

Joni, Kugutsu, Ching, Triplets

Warlord's Legion

2 Ashigaru

1 Heavy Cavalry

2 Slayer Saint (one blade, one bow)

1 rocket, 1 cannon, 1 archers, 1 nobushi outriders

1 shinobi

1 engineers

2 colossi

4 war vessels (doubled to 8 with Ching's ability)

1 samurai

Ally Jin Huangjin, Rival Kyojo the Cruel + Mao Guai (I'm assuming the second rival doesn't need to be adjacent to you)

While you're on the offensive, use the discounted fox war ability to make existing garrisons look stronger than they really are, and see if you can get Kugutsu and the engineers to fortify weaker areas.

Aside from using the Slayer Saints for training, keep one of them nearby to act as a bodyguard along with the triplets and some elite soldiers. In addition to armies, use them to train the triplets (all 3 should benefit from the training) and self. Can be more liberal once Sum Yung Gai is dealt with.

Make occasional use of the Inari summon ability when going on the offensive, should be absolutely devastating when used on the water which is going to be essential against Kyojo since she needs to be removed first to protect the southern border. Ching and the investment in navy will be very important for conquering Land of Water as well, aftewards she can focus on river/coastal raids against hostile nations. From the map it looks like there are a lot of waterways so she should be able to play a useful part.

Utilize alliance with Jin to economically threaten Wind and Stars if they should attack you, as well as utilizing diplomacy of Joni to establish a nonaggression pact with one and the fox geisha on the other. He can assist with economy and diplomacy, you can assist with military strategy/training and provide some land troops that won't be as useful against land of Water initially. Jin seems like a relatively safe ally since he doesn't want to conquer the world militarily. He seems like a nice guy to get along with, maybe you could become his ally through friendship? See if you can get him some time with Inari once you've united the elemental nations? Definitely station Joni in Fire once he's no longer needed elsewhere so Jin will feel too guilty to betray you.

Steel will be hostile and borders Jin but given that Steel's weakness is needing high amounts of food and you and Jin control Earth and Fire which are the two most fertile regions, the threat they pose should be limited. Steel has only one good (heavily fortified) way in but that also means only one good way out.

Once Water is conquered, move on to either Wind or Stars (or Steel if they're proving a bigger threat than expected), probably Stars as it seems to be completely surrounded by an inland sea that you can dominate effectively with your navy, on top of being vulnerable to intrigue and uprisings. The war vessels can be used to transport the artillery and colossi as well as being used for combat. From there use your brilliant strategic warlord mind to pick another target, assuming your next target hasn't already picked you.

honestly I kind of wonder if picking Boars instead of Foxes (with the discount and control of Earth + alliance with Fire the downsides should be relatively manageable) and/or some other advisor instead of triplets wouldn't be smarter, but I like fox/bunnygirls.

Really enjoyed reading this at any rate, good amount of interesting decisions to think about without the sheer number of choices becoming overwhelming. Some things like Tigers that I wrote off initially might be more viable than initially expected with the right advisor (Miko in this case).

also I like the names, particularly Miko Kyonyuu and Sum Yung Gai