Worgen Race idea: All units start with inbuilt timer, when timer ends the units get buffed, become uncontrollable and attack anyone in sight (prioritizes closest target, secondary priority enemy target) . Thus player has choice to suicide the units before timer is up, or send them in strategic death raids in wide formations, or as meatshields. The player disadvantage has to be balanced by low cost of training, low upkeep requirements and generally lighter economy. Also a specialised caster unit that can turn low HP enemies into Worgen thereby providing a massive 'bulk zerging' ability.
If you would like to make some changes on the storyline, I will keep in touch with you and give you a plan mission by mission. I hope to finish this within the next few days (pardon the cheats, I just want to find out the story and how youve set the triggers )