There might have been more strategically interesting battles for Napoleon, but we are not Napoleon. It is much easier to make an interesting, challenging, and a I-won-I-am-so-happy feeling in the medeival period as apposed to the age of Napoleon. Sure, people were still vicious (we always will be), but I agree with Zenicetus. Rows of men carrying early firearms marching, shooting and dying in unison is nothing near the fast paced rush of a mixed calvary/infantry charge laying waste to some stationary soldiers who, noticing the charge, sh** themselves. I think it just is more of a rush.
But backe to why I think it should be Medeival as opposed to Shogun is because the extreme cultural differences, the fanatics from all sorts of religeons (though mostly Western Christians), and the beleif that God had chosen the royalty personally. Also, the sheer cruelty that the Europeans treated their enemies with was unbeleivable. In Japan, honour was showed even to ones enemies, which makes for less backstabbing.