The person you link to has borrowed (or plagiarised - there's no citation Edit: /u/Iguana_on_a_stick points out they do reference Eckstein on page 3, I only Ctrl-F'd the first page. My bad.) their main argument almost entirely from Arthur Eckstein's Mediterranean Anarchy, Interstate War, and the Rise of Rome (2006). Whether this view is accurate is largely a matter of interpretation and debate, but I think it has a lot to recommend it. Eckstein shows how militarism was the rule across the Mediterranean at this time: Rome existed in a dog eat dog world, in which brutality was the norm. We must therefore look for other reasons for Rome's successful expansion than the idea that the Romans were exceptionally belligerent. Eckstein perhaps pushes his case for "interstate anarchy" too far, arguing for example that international law was non-existent, but his "realist" model is still a useful way of understanding the period.