But what if someone's English name is 'Comrade'?

Seriously, it could happen. From Xinhua:

A recent survey on "how you address your peers or bosses" conducted by Zhaopin.com, one of China's influential web sites, showed that 66 percent of Chinese employees call their peers by full name or simply given name, Seventeen percent call their peerswith their English names, 5 percent like to address their colleagues "brothers" or "sisters", while only 1 percent is still inclined to use the term "comrade".

The sample survey picked nearly 6,000 respondents from governmental departments, foreign companies and state-owned enterprises.

Most staffers working in foreign businesses, usually address others with English names like Joey, Ross or Monica, which have become well-known among Chinese empoyees after the popularization of "Friends", the American sit-com.