"In honor of our fathers" - "One Khan, One Clan" [Campaign 3, Mission 2]

I did pretty much the same, except for the Assassin upgrade – I chose Executioners. They are powerful in melee combat, which is exactly what I needed them for. As for the Shaman upgrades, I definitely agree that Daughters of Heaven is the way to go: the hero essentially gets the Chain Lightning spell for free, and with a free move to boot. However, I would still choose the second upgrade for Centaurs.