I'm no plant / agriculture expert. Thus having no idea about growing plants, I just take care of them based on trials and instincts and pure luck.
One of the things I observed about them is that they tend be more lively when they are grouped together. Their branches usually grow and bend to the side where there are other plants. They hold hands (stem intertwined each other). They kind of protect each other by giving shade or a support. And, having a very small space at home, they don't really mind being crowded with each other.
In this pic are oregano and tarragon (the long-stemmed one). I bought them together, and so they became some sort of partner. So every time, I rearrange the plants, I always put them beside each other. It's because I notice oregano loves to reach out to the very prim and proper tarragon. And, somehow oregano's 'messy-looking' trait has rubbed on tarragon. Tarragon used to be this with straight tall stems, now it's like going and pointing anywhere like the oregano.