The original Jungle rules prevented the opponent from examining unspotted stacks. Im assuming this was changed, but I havnt tabled a newer pacific game yet.
This coupled with the fact that in Guadalcanal, the USMC typically has 2-3 leaders per unit, creates entirely absurd logic of hiding your riflemen behind the horde of Majors.
There was also one scenario in the original Panzer Grenadier that called for one side to physically place smoke counters on top of all of their stacks to prevent the opponent from examining them
.
Such are the quirks of the early rules I suppose.