What kind of ruler was xerxes ?

Basically yes, but much of the decisions were made by his generas..They all basically managed not to take advantage where they could(numbers,unity), and the Greeks took advantage of the shortcomings of Persian army superbly(they drove it on ground they wanted,on home rules,relied on their armor and strength which is the game Eastern armies never did well). So yes,he was...even more compared to Geek ones.

If you make it more clear i can answer it

The exchange of foods between the new and old worlds