60 was chosen by the Ancient Sumerians specifically because of its divisibility by 2, 3, 4, and 5. Today, 60 is considered a superior highly composite number but that bit of theory wouldn’t have been as important to the Sumerians and Babylonians as the simple ability to divide 60 by many commonly used factors (2, 3, 4, 5, 6, 10, 12, 15) without any remainders or fractions to worry about.

Medieval technology is vastly more complex, broader in scope, etc. compared to the Stone Age stuff on Primitive Technology. It’s actually extremely challenging to go from scratch like he does and then achieve medieval-level ironworking. He can barely make a few little iron pellets which are excessively-hard (too much carbon) and need further processing to become workable. He is a very long way from building a proper medieval smelter capable of producing pig iron or other cast iron products.

Same with any pair activity. Paddling a canoe is no fun if one person doesn’t like water and wants outta there ASAP!

Perhaps this map will help:

To get from Iran to Israel, the Iranian soldiers would have to cross Iraq (and Jordan) or Syria, both very unfriendly countries full of mountainous terrain. Not a viable ground invasion whatsoever!