Firstly he was a good publicist and claimed victories for battles which were actually draws. Next he used his army's ability to forage on the move to march faster without a huge slow moving baggage train so could get his forces to s crisis point quicker than the opposition though this would upset the locals where he was marching through which would come back to bite him later. Next he attempted to fight opposing armies in detail, so use the large part of his army to batter away at a smaller army until it surrendered then turn the army towards another force which was being delayed by a smaller group of his army and defeat that one in turn, continue to repeat his until all opposition is crushed. Finally unlike most armies he didn't bother with sieges where his army potentially could be tied down in the same location for weeks instead he either took places by storm or ignored them and defeated armies in the field until there was no armed forces left to defend the towns.