OrBat SG2

One thing that is confusing me (I'm from a Navy Background, not
army).

It seems to me that it would be worthwhile having 2 or 3 rifle
platoons and a single platoon of PA.  Is this not done because
of maintenance reasons or does it just not give the correct
feel since nobody seems to do this?

TIA

Roger (who obviously has no clue how high the atmosphere extends)