You cannot compare hashrate reported by the pool so precisely.
It is calculated with the actual shares that you send.
Therefore, it vary depending on the day you mine, the difficulty, the number of miners, the pool hashrate, network congestion, the latency, luck factor, and so on...
Better run your own tests... Lots of smart words put in one sentence but have no meaning all together.
lol u cant use pools numbers to compare. once ur up and once down.