I have the same issue like you... I hope that soon there will be a way to set people into groups, have the possibility to name them and then include them into task to easy this nightmare problem
Same issue here with not being able to assign tasks to multiple people without selecting them one by one. I like Roberto's idea about being able to create groups of people, then assign the task to a group.
Hopefully someone will pipe in or develop a solution for us.
Not sure if this will help anyone else, but I found a way to add multiple followers easily. You can simply copy/paste a list of employee names that has "@" symbol in front of their name into the task field in Producteev. Now they are all following the task.
It still doesn't solve the issue of assigning them a task, but thought I would pass that along. So from an Excel sheet it would look like this: