Questions for determining LOS from mecha to mecha.

The book states to determine LOS from mecha to mecha using the hull of the mecha instead of the base. I found this very difficult to hide a Glaug behind Regualts as the Glaug can just be seen between the Regults. Granted we were using an open table as well. I was using the base for my first two games am I am thinking using the hull is better as some mecha are much smaller than their base. Is this also intended for mecha assembled using the flight bases?

Researching some more, it would seem according to the book you measure distance from model to whatever by the base and you determine LOS from mecha torso to mech torso.

Thanks