Exactly my point, I'm not blaming other zones for this. When there is requirement for locos in other zones, they can allocate directly to them. But why use LGD locos for other zones when there is scarcity in it's home zone? I know that other loco sheds too provide locos to different zones but not to the extent of LGD.
Regarding the document, I've once seen an img where it shows the area covered by respective locos and LGD covers the largest area to every part of the country. I've tried to search but unable to find it. Also, other loco sheds in SCR like BZA and KZJ are used specifically for this zone. But only LGD locos roam around the country.