Complex sentence: The Soviet Union had some 23,000 tanks available of which only 14,700 were combat-ready and as many was 11,000 were in the western military districts that faced the German invasion force.
Split into simpler sentences: The Soviet Union had some 23,000 tanks available of which only 14,700 were combat-ready. Around 11,000 tanks were in the western military districts that faced the German invasion force.