and why? because they sun is so heavy on their big armor, lol
lets see, a marathon trained like sportsmen in light armor
against
a tincan, powerfull but slow and by far not very durable
both making a 40 km walk with occasitional fighting
+ burning sun from the sky
who is more likely to adept?
Also there maybe the returned way.
Very cold snowy map/weather. Those medium/heavy armor may stay warm a bit longer(mmm how is that with tincans in the cold? they would need a pelty fluffy armor? otherwise their dingong just freezes to the steel)