Complex sentence: Austria could have been a counterweight, not only politically but also because of its predominantly Catholic population, however at this time it contained a much higher percentage minority population than its Prussian counterpart and rival to the north.
Split into simpler sentences: Austria could have been a counterweight, not only politically but also because of its predominantly Catholic population. Austrian at this time contained a much higher percentage minority population than its Prussian counterpart and rival to the north.