Right - but they had a chance to make the new currency equal to the currency it is actually pegged to, and they didn't. All they had to do is say "we will exchange 1 Cg for every 1.79 Naf you have." It's all the same in the end, and would make transacting between $$ and Cg trivially easy forever, whereas the exchange between Cg and Naf only happens once.