Theory: There are Haliax and seven Chandarian

Proposal
There are seven Chandarian and in addition there's Haliax. 8 in total.

Reasoning
As per the reference where Skarpi mentions the Chandarian, "Haliax and the seven". This strongly indicates that Haliax isn't counted among the Chandarian - The seven. Haliax is the leader and the Chandarian is lead by him.