LC Large Infantry Squads

[jivemi]

The Russians start out with 13-man infantry squads for Barbarossa (June '41).

1) Do these squads automatically downsize to 10 men later on, or must that be done manually with the "Change" routine?
2) Is there any disadvantage to leaving them at 13 men for the whole campaign (to April '45)?

Reason I ask is 'cuz the 10-man squads available have either F-1 grenades, AT mines or Molotovs for AT work. Since my guys already have Molotovs (Pen 9 vs AT mine Pen 6) there isn't much incentive to switch, except for easier transportability. Thanks.