In late clicker heroes, grinding is hard. After zone 1 million, you might need rubies and lots of hero souls as it take 8 days to get 755K zones, and that's not even counting to zone 1 or 2 million! Here are some tips:
Playing active is important. After getting enough hero souls, you can get clickstorm's duration to almost a day. Since clickstorm's clicker goes even when offline, you can get chain combo. Also, Juggernaut and Pluto can get MASSIVE gold and DPS. You can almost get permanent 59% Crit chance so it is like a treasure chest; Mammon's gold on Mimmze's gold just like Fragworth on Bhaal.