Shields in warfare were used up to the time of guns. So that short time period goes from 15th Century BC. Until today.
Rick as an ex policeman would know this and know the benefits of body armour against people with a lethal bite.
Rationing gas isn't the issue, the resources to get it through the system would have broken down. No one would be baking biscuits in a normal oven. Flour would be a problem. Also water would have to be taken from a river or well, then boiled. Utilities we take for advantage would be gone. Except electricity, people would be raiding places with solar panels and even using windmills.
Farming while they were in the prison was a daily routine. This new location seems not to have any problems finding enough food.
Also no settlement is safe with woodlands coming to the front door, wood is a great resource for heat and decent walls.
The daily struggle to stay healthy, fed, watered, and alive, besides death from zombies, would elevate the series to a new level.
As for Glenn, I thought he was getting his innards eaten. What about Rick stranded on top of the mobile home? Time for a clean out of characters, new leaders maybe Abraham, Michonne or Daryl take the lead and take the series on a route.
With all my complaints I'm still addicted to the series.
Yes Vikings is a bit PC. It has the annoying habit of throwing in pointless 1 minute love scenes.