It's common for international cargo rail to switch out locomotives and re-split wagons according to where they need to go - there's absolutely no need for a sin

It's common for international cargo rail to switch out locomotives and re-split wagons according to where they need to go - there's absolutely no need for a single locomotive to handle all the differences accross countries, switching locomotives between (long) electrified and (long) nonelectrified segments is relatively cheap and fast. Track gauge is a different issue, in transit between China and Europe you'd have to switch somewhere, which takes some effort.