depends... usually youll want the attack hero because chances are your intel hero wont be able to do enough damage

however i guess for something like a scout bomb i suppose the intel hero would be better as it will only last 1 round anyways. That being said you should have enough warriors to protect your archers in any case and who cares if you lose a few more warriors...

i guess the best answer would be if you want to be the MOST efficient use hellfire's damage chart to figure out what you need in troop #s to make up for the low attack of the intel hero. To get your intel hero to fight youll need to move all attack heros out of the city though if you haven't leveled up the attack at all.

That's assuming you're online, if you're offline then the attack hero.