I am trying to do area computation stuff over whole of Indonesia and as such, am using the following projection:

http://spatialreference.org/ref/esri/asia-south-albers-equal-area-conic/

To make this projection work over Indonesia, I am following the guidelines give at the following link:

https://geonet.esri.com/thread/30524

The recommended modifications change the following:

central meridian: 115.0 (from 125)

standard parallel 1: 2.0 (from 7)

standard parallel 2: -7.0 (from -32)

latitude of origin: 0.0 (from -15)

I think central meridian and latitude of origin do not impact distortions in any manner. However, why is it that the standard parallels should be 2 and -7? The entirety of Indonesia does not seem to be lying within these latitudes. From my inspection of the map, the entirety of Indonesia would lie somewhere between 6 and -11. Wouldn't these be better choices? How does a change of standard parallels/secants impact the computations?