[moderation]

High resource troops don't necessarily survive longer at all stages of the game. All the armor in the world won't help if you run up against AN attacks like R'yleh's and heat and cold auras will still kill your troops, not to mention SCs and thugs. Ulm has really high resource high protection troops, but they will still be squashed by tramplers. A lot of times low resource, high damage units might be more appropriate.

Armor works some of the against some things. Sometimes it's better to have blockers like MA R'yleh's 5GP/1Res Lobos. And units with natural protection like crab hybrids and hydras are fairly durable while only costing 1 resource. Of course, high resource troops can be useful, but since you have to mass them over many turns, you'll have to pay upkeep and you will have to plan ahead to have enough troops on the field.

There are pros and cons to high resource troops and productivity, but it's hard to say that resources are nearly as useful as gold the way the game is right now. If castles had to be built with resources, as others have mentioned, production might be useful.