Peter sorry for the delay. I'll leave this post here until i can spend this weekend dumping the workflow we at our company came up with. In a nutshell we would create a 4th ticket type that allows ticket linking. Rock bottom simple until we can get more features into WHD. This would allow all techs to receive assignments as child tickets of an overall ticket being used to drive the entire initiative. Its missing deadlines and skills/task requirements but i'll need more time to map out an example of how that would work.
I was looking through the SQL database to see if you really can just add a new type and just copy the linking feature to its own proc.