to be fair the persians did not really have a better option, besides for that pass to the rear of the greeks that may or may not be historical... only other ways the persians could have taken would have added many more months to their campaign, thus opening themselves to more attrition and leaving themselves open to being nibbled at. thermopylae only seems like a supid choice for the persians because how it turned out, but when the decision is taken into context of the existing alternatives, it really wasn't such a bonehead choice.