[standard][128.german]goods Waggon speed limits

[Huperspace]

a lot of waggon support 120km/h around 1965-1975. But some only get one after 1990 or 2000 or sit at 100km/h.
all goods waggon have max 120km/h empty and 100km/h loaded per db waggon catalog. (maybe due to speed regulations).
ether make all 100km/h or all 120km/h. else balancing is hard. or extend the game to support the 2 different speed limits, loaded/unloaded).
Balance tips: make waggon groups: light but low cargo; heavy but alot cargo; medium but fast. (around the same time +-5years)