Yeah, this makes sense. But I don't see how he could rebalance the accounts by moving bitcoin. Fiat will accumulate where the coin price is higher, converting it back to bitcoin would erase the profit and bring the operation back to break-even, no?
I had an example worked out but I cannot find it now, both Google search and the Forum's search seem to be broken.
Anyway, suppose at the end of the month the arbitrager's Bitstamp account gained 10,000 USD while the Huobi account lost 20,000 yuan (so the two together made a profit). Then (to simplify the math), he waits for a moment when two exchanges are momentarily in equilibrium, that is, the price at Bitstamp is x and the price at Huobi is 6.21*x, and have good liquidity. Then the arbitrager buys N BTC at Bitstamp (slowly so as not to disturb the equilibrium), sends them to the yuan account, and sells them there (ditto); where N is such that +10000 - N*x = -20000/6.21 + N*x. Then both accounts will have made the same gain.
This rebalancing can of course be done simultaneously with the arbitrage, even out of equilibrium, so that the two accounts have the same profit at all times.