So, Fomenko does address coins. Firefox is misbehaving so I can't give exact pages, but his arguments are: 
 * coins are a relative dating method: if in a grave we find a coin minted in the time of Julius Caesar, we know that the grave was made during reign of Julius Caesar, or later, but the coin itself doesn't tell us when that was; 
 * antique and medieval Roman coins are plentiful, while coins from dark ages are few, and Fomenko maintains that this is left without sufficient explanation; 
 * different rulers used different names in different parts of empires they ruled, and this is reflected in coins (some ruler names are dated to one period and some to another); 
 * dark age coins that are found Fomenko attributes to local rulers, forgeries and so on; 
 * Some coins actually support NC; for example, those that refer to Ceasar as emperor. 
 And in any way, unless there is someone who is an expert in the field and has been criticising Fomenko's assesment of coin dating, it shouldn't be in the article.