Here we go again...
If you hadn't been around on the forum for a long time, I'd think you are a troll.
So, this time not the Alpine mountain-cross is the
propaganda in your opinion, but the US (Union) soldiers in the Western sets and the disproportinate lack of their Confederate counterparts, or their flags.
There are about 2 to 3 popular (though not allways politically/historically correct) views about US soldiers in the Wild West-theme, especially with kids playing cowboys & indians in their backyard;
1. US soldiers coming to the aid of civilians in distress, which are being robbed by bandits
2. US soldiers coming to the aid of civilians in distress, by fighting off attacking Indians
(I'm European and ''Indian'' is what we here have called the native populations of the Americas for the past hundreds of centuries, so please excuse me for not calling them Native Americans as a politically-correct US-citizen now should do)3. US soldiers fighting each other during the US Civil War
During the 1970s and 1980s, Playmobil's soldier-part ot the Western-theme was focused towards 1. and 2.
During the 1990s, Playmobil's soldier-part ot the Western-theme was focused towards 3.
During the 2000s, there was no Playmobil Western-theme.
At the start of the 2010s, Playmobil's soldier-part of the Western-theme is apparantly again more focused towards 1. and 2, though they offer a Confederate soldiers Add-on set in their DS-assortment.
The above should explain your observed lack of enough Confederate flags.
Btw, in Europe, the Secession of Confederate States is still often considered as associated with slavery in the US.
It is also often considered linked with (Neo)Nazism, racism and the ''Cuckoo Clan''-folks.
How much this could be a contributing factor in the lack of more Confederate flags in Playmobil sets, you should ask Geobra directly.