If you follow the link Sailguy provided, it shows the pertinent information in the specs. Yes you can run the numbers forward and backwards but it doesn't change the spec showing the running wattage of 560 and an EER of 10.7 on a 6000 BTU unit. We can get there your way to check LG's numbers.

6000 BTU/10.7 EER = 560 watts just like the specs say and that is the number that we need. What we don't know for sure is the starting load. That is what is needed to size the generator properly.

I do not see where your numbers are coming from in the link. I don't see the EER number you used in the link. Maybe the link has changed. There is no error in your math. Why not just take the easy path and use the numbers that are specified by the manufacturer rather than complicating it?

And yes your point of the loss of efficiency as the ambient temperature around a generator increases is a good one. Typically if the small generator we are discussing can start a motor, it will have no problem running it.