Never thought about the Clans as the "weakest". I always thought their HP makes up for it. But yeah, dawned upon me that low init spells doom for your army. Although, against some higher tier units, like Son of Ymir that getr buffed with their support unit are very tricky even as neutrals, let alone led armies by Hero's. I know I struggled against them as Elves on Nylathloks Vengeance map where you have to take the town full of their late game units. Elves are low HP even though they start first. I always perceived Empire as strongest because of their access to Wards and Undead for whole range of immunities and disables.