I use Russian language, I just role play being in the zone, and they speak russian there. I finished the game like that and had no issue, because everything they say gets translated in your PDA. And I also use slavic language, so Id say I understand 10 - 20% of what they say in Russian.
Yes its a bit hard core, but to me, absolutely worth it
I hope you enjoy the game, give it a moment, the Cordon is just a rookie place... let the game grow with time, its gets really really towards that 10/10 territory, for me.