Size looks neat—big plants at the back, small ones in front. But care-wise, what really matters is how quickly each pot dries. Some plants in small pots drink water like crazy, while others in bigger pots stay moist for days.
If you group thirsty plants together and slower-drying ones elsewhere, you can water more accurately. One corner might need daily attention, while another is fine every two or three days. You’re less likely to overwater succulents because they sit next to a fern that loves constant moisture.
It’s a practical way to arrange your mini jungle according to “behaviour,” not just height.