ICG has no experts on ancient coins on the payroll; they are in
Colorado Springs, and use local people as consultants. I've never
noticed a fake in one of their holders, or a really badly misattributed
coin either (can't say the same for PCGS or NGC). The problem is that
it is not possible to grade hand-struck coins by a single number (may
not be possible to grade machine-struck coins that way either, but that
is another discussion); you have to consider inscription clarity,
portrait, centering, artistry of dies, metal qualty, etc.

Bob Leonard