Why does the whole network have about 7.6 MH/s hash rate? but all listed pools add together only to have less than 1 MH/s hash rate. Is any big farm extracting these coins from their own pool?
What that doesnt make sense
It does make sense if it were true. It could mean that one farm could control most of coins and later manipulate the price.
It might be a Nicehash buyer. You also have to keep in mind that there are a lot of people who mine on private pools/solo mine. You can't expect to be able to add the network hashrate solely from the pools. This is the case for most coins. Even bitcoin which is the most known coin with little privacy has 10% of the network as "unkown".