>but who were Ed Sheran (sp?) and his barbershop quartet
>fighting for? Their armor looked very similar to the one Jamie
>was rocking, but I can't imagine they are with the Lanisters
>since they are so humble looking and were actually nice.

The one guy even said right on the nose "men go off and fight other men's wars"

They are just dudes who happen to live in the part of the country that fights for the Lanisters, but it doesn't make them all awful people. Arya realized when hanging out with them (and after killing every one of Frey's men) that there are a ton of innocent victims in this thing. It was the first time for her in a long time that every interaction wasn't just life or death and she got to just talk to normal people caught up in the same bullshit game she is caught up in.