Which hyd excavator pump/setup for a newbie

[Mike205]

Just been informed by Der Getriebedoktor, the supplied pump with their Bruder cat 320 conversion is the 380 ml pump. The same or similar to the Wedico Cat 345d I believe, runs at 12 bar on the brushed motor. Could somebody in the know inform me what the ml figure means in pump terms. Is it the capacity of the oil tank, or the ml pumped per minute.
Does it mean the 380 would be able to supply more / bigger cylinders than say the 200 size , but at the same pressure ?
Thanks