Only data dependancies determine execution order. If there is a wire going from one loop to another, the first loop must complete before the second one starts.
If there are no wires between them, the loops all execute at the same time (or at least, they might).
You can not assume anything about execution order if there is no data dependancy. Even if it works on one machine, it may not work on another machine, or even when you run it a while later on the same machine.
If there is no data dependancy, you can 'create' one by putting a constant value (for example a TRUE boolean) in one loop, and then wire it to the second loop.