How were interactions between hominins?

Today we are aware that our evolutionary tree is not a linear line, but one has many branches and dead branches. One of the interesting things I have found about evolution is that our species have never interacted with another hominin. However, in the past, there is evidence that several hominins whose timeline were active in the same time as other hominins. For example, we know for a fact that Homo sapiens and Neanderthals interacted with each other, and further, the interaction could have had some impact on the Neanderthals' disappearance. Additionally, In Herries et al. article they discuss new findings within a cave in South Africa. Within these caves, it was discovered that three different hominins (Australopithecus, Paranthropus, and early Homo erectus) occupied the same space around 2 million years ago in Drimolen, South Africa. It is interesting to think about how these hominins would have thought of each other and how they would interact. Based on the evidence, we are aware that several hominin species did interbreed among themselves including Neanderthals and Denisovans, Homo sapiens and Neanderthals, and several others. This must of led to some violence because individuals must have been taken from their group in order for interbreeding to be somewhat successful. I believe there was quite a bit of competition between other hominins based on them being hunters and gatherers. Due to this, there must have been some competition between territory and food. Especially in areas like Drimolen, South Africa where several species of hominins occupied during the same time, there must have been competition due to the limited supply. Despite violence being present within the societies, I believe in some ways they collaborated especially Neanderthals and Homo sapiens with tools. In later hominins, I believed they used some forms of speech to communicate with one another. Especially, Neanderthals had advanced language abilities, but their language is believed to be improved due to their interactions with Homo sapiens.