Looking at the ship backbone by jump range, it becomes obvious which ships are the "explorers".
In the chart I am comparing stock maximum jump range (without any engineering).
The thing that stands out here is that there are three gaps of almost three light years in range between the top-end ships; a gap between the herd and the basic explorers, then a gap between the basic and top-end explorers and then another huge gap to the king of jump range, the Anaconda!
Personally I think those gaps need filling, probably with Passenger ships and medium traders..