Complex sentence: These troops often became experts in defeating the average soldier of the day and had the economic backing to do so due to their importance to the governing body and as a result they advanced military training and equipment as far as it could go.
Split into simpler sentences: These troops often became experts in defeating the average soldier of the day, and had the economic backing to do so due to their importance to the governing body. As a result, they advanced military training and equipment as far as it could go.