understand what you are saying and agree with you. However, the argument these people advance is not concerned with the interpretation of the Bible but with how closely a given translation matches the original source text.
The solution is simple though not easy, learn Koine Greek
That website looks like a great resource.
As far as arguing translations, ask which 'version' they use and why. If they use and trust the KJV, why aren't they Episcopalian/Anglican (assuming they aren't)? If they're anything else, why? The KJV was commissioned by James I (the former James VI of Scotland) to counter Calvin and the Geneva bible. If the KJV is the 'real deal' how can the Methodists not be Anglicans?
If they're Presbyterian, why aren't they using the Geneva bible? In fact, if they're Baptist, why aren't they using it? If Calvin et al weren't accurate in its translation, what else did they miss?
Why would Calvin, Blackmon, the KJV committee be any more capable than St. Jerome, who was a native speaker and acknowledged linguist/scholar? If Jerome and the Catholic Church have some agenda, whose to say these later translators don't have their own agenda?
There's a joke Southern Baptists tell on themselves: the new Baptist church down the road from the old Baptist church is evidence of a Bible study gone terribly wrong. That reveals more than they realize.