well with lgb i have much more tolerance regarding the protypical-ive grown used to mixing and matching all sorts of things i would not normally (within reason) -roadnames, colors, eras, -you have to run what you have and what you can obtain
here are some pros to 2 axels
first: run what you like-I have a lot of LGB but, i too have a US starter set (which is what im guessingyou have-the 2-4-0 loco ) with the shorty US style 4 axel coaches and have no qualms running a 2 axel US style baggage car with them
second: the 2 axel cars are often more available, and were often priced lower on closeout, becasue i think here in the US most folks prefer larger US outline equipment and the 'euro' outlines and crtain models just didnt move as well-the quality however is always great- -those days of closeout pricing are passing quickly however
third: it is my experience that the shorter wheelbase of many of the 2 axel models in particular, seem to track better on tight radius and rough and tumble (less than level) outdoor track
fourth: get what you can now -i predict everything lgb will only rise in price thanks to marklin-and probably significantly
finally: 2 axel cars are easiest to rerail