Although you are all correct about getting banned jumping in and out of groups in instances, thats not what the link I gave is talking about. He mentions nothing about instances.

what you are doing is killing it yourself, there is nothing even remotely slick about using 26 characters to kill a mob
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I do exactly what he is talking about. Guys are similar level so the mobs are not grey to anyone. One character tags (in my case one group tags), and other characters help kill the mob (in my case other groups help kill the mobs). Its exactly what he is talking about.

Youre way you will only get a % of the xp becuse you dident do all the dmg, so rly its faster just by doing it in groups.
Thats not correct at all. If the mob is not grey to you or your helpers the tagger gets 100percent of the exp.