Complex sentence: Although there was no permanent formation above the regimental level, senior officers were largely recruited from aristocratic circles (and commissions were generally sold to the highest bidder, regardless of competence), the Russian infantry was considered as one of the most efficient of Europe.
Split into simpler sentences: Although there was no permanent formation above the regimental level, senior officers were largely recruited from aristocratic circles (and commissions were generally sold to the highest bidder, regardless of competence). The Russian infantry was considered as one of the most efficient of Europe.