Cargo allocation: "% space allocated" not actually allocate percentage of space

[qunow]

I have mentioned this elsewhere a while ago but let my write a formal bug report for this.
When editing a route, the legends are telling players that they are editing the % of space allocated to each cargo type, as you can see in http://i.imgur.com/IAwNeZT.png
However, for some aircraft type, it does not actually reflect the % of space allocated, and instead used to indicate the % of payload allocated to each aircraft type.
For instance, with aforementioned ratio on 734F the % of allocation would become like this
http://i.imgur.com/dxsIxJy.png
Which mean it is actually going to carry 25% CL payload, 50% CS payload, 25% CH payload, or in other word, 10%:45%:45% space allocation
The situation is further confused by the fact that the allocation method only work like this for some aircraft type in some percentage configuration, and in other aircraft types the distribution actually follow the % of space allocated.