First and foremost, the AI will deploy any unit on its mat that it can afford to deploy with the Corra it has. If the AI can afford multiple units on its mat, it prioritizes the highest letter possible (A before B, etc). If there are multiple elites of the same letter than the AI can afford to deploy, it deploys the leftmost of those elite troops. After paying the Corra for that elite, if it still has Corra left, it runs the same check again to see if it deploys anything else.