Roman Legions seem too weak

[Intranetusa]

The Roman infantry was among the best in the world, especially by the time Marius made his changes(most likely started prior to Marius). A combination of arms,armor,training,discipline and triplex acies made them very formidable.

Actually, the quality of Roman arms and armor was often lower than their opponents. Their weapons/armor was cheap and produced in mass.

Their weapons and armor (chainmail, and later the famous 2nd century CE iron band armor) were made of carburized iron of varying quality. Roman metallurgical skills were actually quite poor compared to other civilizations at the time and they never developed steel.