Pretty much just N and HO, which is why this is wierd. The most likely solution would have been HOj for the not-bullet trains - i.e. make those guys larger 1:80 scale and slightly fudge their wheels onto HO track. That seems the common model solution in Japan and would have had the added benefit here of making the bot and combined mode engineering simpler with the trains all closer in size. But seems they might be going HOn3.5, i.e. keep them all to scale - 1:87 - and the not-bullet trains run on 12mm gauge track instead of HO 16.5mm. But that seems super uncommon. Will be interesting to try and accurately measure the gauge of Getsuei's track from the CAD and see if it's 12mm.