Germany
It's probably because Axis are incredibly forgiving and easier to play in team games. You have to really outplay your opponents in order to win a large team game as Allies.
-Smaller squads
-more likely to be wiped
-fuel & popcap concentrated on less units, means losing them is a bigger setback than losing one as allies.
Hence, what you say is not true.
Balance in even match ups (by rank) in 3vs3+ depends mostly on the map.
If you have less flanking options : Axis favored
Big, wide open maps: Allies favored
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