Sequential and parallel execution with different number of users

I have the following use case

For my load test I need to setup my system state, I do this with gatling because its quite handy.

First 1 users needs to setup the global system state, this takes approx 20 seconds
Now I want to setup different sub parts of the system in parallel, this should also be done by just 1 user, in the graphic below this are the “Setup Data A” and “Setup Data B” parts. Setup Data A takes ~3 min and Setup Data B takes ~15 min (a lot of requests)
After the Data setup for A or B is done, more users can start to load test, those users should of course only start after all the setup for the specific part was done.

How would I model such a setup with gatling?

`

Setup
Global System State
1 User

/
/
/
/
/
/
/
Setup Setup
Data A Data B
1 user 1 user

Load Test A Load Test B
30 users 50 users

`

What I currently have is this:

`