Your weapons are not as relevant as this game is about abusing combination of perks:
Having multiple teams to cover other parts of the world have nothing to do with battle casualties and attrition.
How is more hp make it any different from BB5? This would have effect only if you don’t use perks properly and to have proper perks you have to keep your team alive - which leads to all or nothing strategy. Of course you can ignore that, but it’s clearly not what they game wants you to do.
In old x-com there was a very simple principal - most of your early hires will perish, maybe 1 out of 7 or 10 will survive till the end game and that’s how you get your A Team for a finale of the game, not for early midgame. Loosing your soldiers was a part of the development strategy overall as it gives you a “statistical” indicator if you are moving in a right direction. You would flip their weapons and armor almost every mission. There are mods for OpenX-Com like XFiles that add all the personality that was missing in original X-Com and you can save scum to save characters that are dear to you, but the game itself is not build around keeping a Joe from a tutorial mission till the end game or you will have a hard time.