Maybe this helps:
V1.05.18 – September 6, 2011
19) Changes to Morale Rules
a. The following units receive bonuses to their National Morale: All Cavalry, Mountain Airborne and Air Landing units, and Axis Allied motorized units +5, German Motorized Units +10, Soviet Motorized Units (from Sept 1942-August 1943) +5, Soviet Motorized Units (Sept 1943-end of war) +10.
f. Shock Armies provide their +5 bonus for non-guards units which don’t already have a specialty bonus. Guards Armies provide their +5 bonus for Guards units which don’t already have a specialty bonus.
Shock army will provide +5 bonus for the non guards units which didn't get speciality bonus (rifle units), guards armies provide +5 bonus for the guards units which didn't get speciality bonus.
I can go in more details, but there are thoughts to drop Army HQ morale bonus and substitute it with supply/replacement bonuses.
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts."