I’m excited to answer first questions about AI Studio on the Forum 
Your reasoning looks globally correct, but some details might cause issues.
Some suggestions
1- Try to more consistent with the keywords (don’t use different variations of the same term). It’s a bit like Lego blocks, if they are slightly different, they might not fit perfectly (sometimes) 
2-
Create a duplicate task for each variation requested
Technically speaking, the action “Create a duplicate” doesn’t exist, you might have to explain more what you are expecting here (eg. “Create a task with the same Task title… and the same description”?). Have in mind that if you need the description to be transferred to the "duplicate " task, you need to have the AI variable in the description (clicking on the detail of “Create a task” (View all fields) > Go the description > Add variable > Fill by AI).
3-
“Change task title of each duplicate to align”
Here, technically speaking, AI Studio is not changing anything (or that is not visible in your workflow as an action), it is just creating a task with a specific name.
The format of instructions (at the step 2-) should be : "Task title is… “WP_MOPS_[Task name]” where [Task name] is the name of the task triggering the rule…
4-
Add a number to the end of each variant in ascending order, starting at 1
Same as 3-; this should be combined directly with the task naming instructions
5-
Match dependencies of original task
Match projects of original task
Please note that it is only possible if the task has the “Fill by AI” at the right spots.
And for the moment in the Action “Create a task”, that is not possible to add it in dependencies or projects. Then, you can’t do it this way, even if you give the proper instructions.
Overall, the concept of “duplicate” task doesn’t exist in rules as an action at the moment; and because “Fill by AI” is not available everywhere, it doesn’t work.
If you haven’t done it yet, I would suggest going through that nice new training
Hope that helps 
Arthur