@barnee
We mostly see the 1st US Desert Army and the 1st German Desert Army.
UK most often have their Tank Army fighting in the Western Europe sphere - supported by a US Tank Army (after D-Day).
We would not recommend an increase in Panzer General / Tank General units, since this could unbalance the game. We have already play tested this.
It took us 3 years to find the right combination of Armies - with Play Balance, Game Enthusiasts and Historical Aspects in mind.
The number of Panzer Armies & Tank Armies that are part of the game, challenges the players to prioritize their Armies - both as a Strategic Reserve and as Frontline Combat Formations.