I concur with him. There is some strange thing with mining income. For example, I have 2100 h/s with equihash. And crypto-coinz.net predicts 1700 coins per 24 hrs. On suprnova I get only 1500. On miningspeed 1200. And so on. Always less then prediction, never more. (There was luckpool which actually could give a little more (with luck factor)  but it was quite buggy so I abandoned it)