A Guild is or should be atleast about teamplay.
To just be in a Guild for the Rewards and having the attitude of gollum is contra produktive for the Evolution of the playerbase of your guildmates.
Your individual Achievements in getting a higher gp with unlocking more toons helps yourself in other ways then a Guild raid. Arena, beeing prepared to unlock new upcoming toons. Bragging Rights etc etc. But when more then One player has the same damage done Why should One be allways first just cause he got an higher gp due to having more toons which Arent even needet in this raid?
Same was the old System based on the ally Code.
Of course it would be better if everyone who does the same damage gets equal Rewards but eventually it evens out when the ranks are randomized.
Just Keep in mind it helps all of the guild which will help you in the end cause your guild can then Rank better in tb and tw for better Rewards.
And most important Never forget... its just a Game