Most of the arguments for zombies being of better value are contingent on the assumption of raising to replace lost wounds. This is a very variable application as there are many variables to consider. Static CR, WS and strength of attacker is one that will change many times throughout any given game.
While zombies do raise at a faster rate, 3.5 per SUCCESSFUL casting. Now, lets say combat was already joined. Beginning in your turn, you have to endure 2 rounds of CC before you have an opportunity to replenish those wounds. I think between armor, parry, amd possible wound potential, and crumble the skellys have a better chance of making up those 3.5 wounds. I have seen many games where not a single Invo has been successfully cast. There is a scale effect here also.
But at smaller points unitswise, it gets closer.
While zombies do raise at a faster rate, 3.5 per SUCCESSFUL casting. Now, lets say combat was already joined. Beginning in your turn, you have to endure 2 rounds of CC before you have an opportunity to replenish those wounds. I think between armor, parry, amd possible wound potential, and crumble the skellys have a better chance of making up those 3.5 wounds. I have seen many games where not a single Invo has been successfully cast. There is a scale effect here also.
But at smaller points unitswise, it gets closer.