Three different denominations of currency, all in coin form, and each one divided into a hundred pieces for the next smaller set, is a terrible coinage system. Just imagine trying to make change for pretty much anything. You buy something worth two bronze, and pay with a silver, and now you're toting around another 98 bronze coins. It's like if money in the US only came in $1, $100, and $10,000, and it would all be in the form of change. This system also implies that there are three different economic strata, and each mostly just uses a single coin for their normal needs, since the values are so far apart. However, that would only complicate matters further, as making change becomes non-optional most of the time, and few would ever convert to a higher denomination for ease of carrying, if it were even possible.