Seems like in the US we totally avoid an option which might just be a better solution in many respects. Why don't we use more two-headed bidirectional diesel locomotives? Simple run around tracks could be built or possibly even available in many cases.
Now you have ONE engine per train instead of overpowering a short train with two locomotives. You have the ability to add a revenue coach by removing a trailing engine or cabbage which increases income. You avoid the costs of building a wye if you even have the room to do so.
Why do we completely avoid this concept? Routes like the Downeaster is an example where this would work well.