Phil, that's all a bit incoherent. I really don't think the Templars had much to do with Greenland, and I don't think anyone else does. Even bishops didn't go there much (a bishop appointed for 98 out of 400 years, and the probability that several of them never even saw the place). Promissory notes would have been small use to Greenlanders, a boatload of hay would have been rather more use, if they could have got one there often enough. Six years of tithes at one go suggests a shortage of boats, not a plethora of wealth.

We aren't, or weren't, discussing why the Catholic Church kept secret latifundia scrimshaw factories in Greenland (though it would be fascinating to see any evidence that they did). We started with a palpably fake "Roman" sword, and a discussion developed of why it took 5000 years from the beginning of seagoing navigation for Atlantic crossings to become commonplace (in either direction, and we could talk about the Pacific too).

Note that "commonplace"- we're talking here about a step change (less than 30 years) from a possible blow-in every thousand years that left no trace, to a complete disruption of society for practically every inhabitant of a continent, thanks to a conveyor belt of ships carrying social, genetic, microbial, technological and linguistic change, and a corresponding worldwide ripple (or tsunami) effect back in the other direction. Including why you might eat an Indian takeaway with tomatoes, chili and potato in it.

Perhaps something was true in 1400 that hadn't been true in 980, and that something was to do with ship technology (you can add gunpowder to that)? After all, something was true in 980 that was still true in 1400, and is still true in 2016, and that's the laws of physics.