Run behavior tree on simple parallel composite

Hi, I’m actually making a shooter AI and I need to make it moving while reloading,aiming and shooting.
Is It possible to run a behavior tree that handle the reloading/aiming/ shooting part as a main task on simple parallel composite? Or should I just make several simple parallel node for each task ?
Thank you!

I spent several hours trying to work out this very basic problem. You can see my solution in this thread.
In my case, Simple Parallel did the trick - however not without a certain ‘gotcha’. I am posting this in this thread in case someone else stumbles on it via google.