This waggons were mixed, as you explain. IIRC another user already reported this long ago (it was Vaclav I think), and I thought it was fixed in nightlies. Not sure about last release though.
For the engine speed, you're absolutely right; I will change their speed to 230 and rebalance them, because it's the max speed they can be pulled at by the 252 loco. Also they have huge capacity that IMHO should be lowered too (at least they had in the past, I'll re-check it later). Thanks fabio for reporting.