I suggest the creation of minor factions wich would have tech from tier I to tier III at least. We should not divide playerbase in matchmaking when use such nations, they would appear along with the main nations within a battle. Maybe matchmaking would take longer time for those who pick such nation but I beleive it worth it. Many of their equipment is already in the game. What they lack in equipment, their shadowing main nation would have. One player cannot carry every equipment into battle anyways.
I suggest some nations:
-Italy: Battle of Stalingrad/Battle of Tunisia
-Hungary: Battle of Stalingrad/Battle of Budapest
-Romania: Battle of Stalingrad/Battle of Budapest
-Finland: Battle of Leningrad/Battle of Tali–Ihantala
-Britain: Battle of Tunisia/Battle of the Bulge/Battle of Normandy/Battle of Burma/Pacific
-Australia: Battle of Tunisia/Pacific
-China: Battle of Burma/Pacific
-Poland: Battle of Berlin/Battle of Normandy
-Free France: Battle of Tunisia
On a long term I also suggest adding new scenarios as: Battle of Budapest, Battle of Leningrad, Battle of Tali–Ihantala, Invasion of Manchuria
I hope my suggestion was useful. Merry Christmas for everyone!