Tactics for the Stronghold.

Question: taking the Griffin Conservatory on the second week.
And level 3 Griffins at that. Building the Horde in Castle + orcs, hero Crag Hack level 7, stats 8 3 2 2, no spell book (nothing useful in the Mage Guild, 2.5k savings). Not enough gold for a full buyout. What is better to take: wolves or birds? Is it worth removing the 2 retaliation strikes and hitting with wolf riders? In short, I have a save, but I don't know how to attach it so that someone knowledgeable can take a look at what's what.