That's right. Assume historical price ticks for assets A and B have the same time stamp. The tick() function runs first with asset A, then with asset B. In the first run asset A has the current price and asset B the previous price. This allows you to snoop the next price of B when the assets are related.

Thus, for trading with related assets in a tick function, check the timestamps and only trade when all assets are up to date. You can store the timestamp - wdate(0) - in any tick function, and trade when the stored timestamps match or are less than TickTime apart. This will be mentioned in the manual.