Considering that when Ooarai wins in Episode 3, they'll go up against either Saunders or Keizoku. My money's on Keizoku because they haven't faced them in battle yet. Although I'm wondering how Keizoku is going to flesh out their forces enough to make the fight interesting. Or maybe it'll be a reverse Ooarai situation, i.e. they'll be the outnumbering force (for once) and so they'll underestimate Keizoku, which will lead to them losing numerous tanks before they finally get their act together.
I'm imagining an alternate timeline where the rest of the world doesn't treat tankery as a womens sport but rather as a military sport and instead of WW1-WW2 tanks they use mid cold war to late and post cold war era tanks. They have a dislike for Japan's modest way of tankery. This interval causes all the main teams of the world's tankery teams to invade and interupt a tankery match in Japan and callout the major tankery teams to match to prove who is the best. (Sidenote: because Maho is studying in Germany she is forced into the Tankery team or just influenced into joining she provides all intel on Japan senshado and gain a neutral hatered for Japan's way of senshado)