Dude, it's not over till it's over! You and Aku are far from dead, anything can happen.
(Also, please share the invincible strategy that assures my victory! I sure could use one!
)
About attacking versus defending, in my opinion that's not as straight-forward as that. Sometimes it makes very great sense to be the attacker, either in the magic phase (to hit before the reinforcements arrive) or otherwise. Or if you mean tactically: if you have fast enough troops and a full length script on your guy there should be no problem, as your troops will engage the enemy before your SC attacks. Another option is to use a non-flying guy, or a storm, to bolster the flanks of your SC. Lots of possible tactics!