It may be that it was common for Scythians to live in wagons rather than houses, i.e., to be nomadic. If the Tocharians were of this group there might be drawings of these ancient winnebagos.
Could be. One of the oldest wheels (of unexpected high quality for its age) was found in this area. The deep steppes were unaccessable to these people without the horse and wagon...the world's oldest pair of pants was also discovered in this area because pants were needed when riding horses.