It's like these folks never played OpenTTD.

I'm on my first playthrough of Space Age currently and while I've got something fairly complex on Nauvis with multiple stops and interconnects and loops and a half dozen or so trains... a lot of my needs on other planets are just point-to-point single train transfers. e.g. running a line out to a scrap patch on another island with millions of units of resources on Fulgora after exhausting the initial scrap I mined out. I don't even need multiple cargo wagons let alone multiple trains to max out my factory's input belt capacity there at the moment... Could the whole thing be more efficient? Oh yes -- but sometimes simple is good enough, and not having to build loops before I got the deep elevated rail support and/or foundations helped tremendously!

I think I was probably supposed to figure out the double locomotive thing in the train tutorial -- I don't remember there being loops on the track there... -- but I'm pretty sure I'd already built at least simple factories on everything but Aquilo before I realized it was even an option. :p