When modeling a scientific process, it is more important to organize the parts in a way that makes sense to you than to list them sequentially.

I would say that this is generally true, except if you're specifically modelling a temporal order of your experiment, then it's important to get the order right.

But especially if you want to brainstorm, of if you want to check if your plan makes sense and is efficient, then you should organize it in a way that allows you an easy overview of the process, which might not necessarily be the sequential order.