Newbie question about bogie pivot position

[Jim Easterbrook]

I'm going to be building a 3D printed container wagon (https://www.shapeways.com/product/HKTYV3YWG/rhb-sb-t) and have just started getting the bits together.

I noticed that the cheap Chinese bogies I've bought have their mounting holes / pivot positions centrally between the two axles, which is what I'd expect. The 3D printed wagon seems to want the pivot position offset towards the centre of the wagon, to make the bogie appear to be centred in the "wheel arches". I had a look under my Kato Glacier Express coaches and their bogie pivots are offset towards the end of the coach, opposite to the wagon.

Someone decided to offset the pivots like this, and the engineer in me wants to know why. Something to do with caster angles? Better tight radius ability?