Has anyone ever considered giving smaller transport (say, 3200 cargo or less) a small thrust speed boost, to make them a sort of true middle-ground between freighters (200 thrust) and all the other, larger transports (140 thrust)? Most people still choose to use larger transports as soon as they can, so I don't image it would hurt the balance much. At very least it might let the smaller transports match a gunboat's thrust speed, giving them at least a slight chance of successfully running away (since CMs don't really do anything useful vs. Train CDs).
Yeah, Small Transports and things like the Albatross should have 160 thrust. Just a little bit more speed to play nice with both balance, logic, and the laws of physics.