I dunno.
I use LTN and I started with 1-1 (one locomotive, one cargo) trains and 1-4-1 (1 loco, 4 cargo, 1 loco). I used the 1-4-1 cargo for higher throughput (mining, iron plates, core fragments etc) and then 1-1 for everything else. This worked well until my systems got more complex and...