luggage weight in high speed trains

I am flying to China and plan to take a high-speed train upon arrival. According to the regulations, it seems that I can bring more luggage on the airplane than on the train, which seems strange to me. On the plane, I am allowed an 8 kg backpack and a 23 kg suitcase with 150 cm total dimensions. However, based on the train rules, this might not be allowed. Does anyone have personal experience with this situation?