I'm all for a personal parser, as information on how to improve your numbers can be found by looking, but I do think a group parser can work if set to a certain limit.

Basically a group parser that shows everyone's DPS, but only to a certain threshold. And that threshold is set by the devs on what they think is an acceptable number needed to clear an instance within a time limit of say 20-25mins. However, to you, it will show your personal number, even passed the threshold. Then it will still have a numbering system, so you could be at number 1 DPS, but to everyone else it will still only show the maximum threshold number but you will be number 1.

In a raid environment, you could potentially set it to show everyone's numbers, but only in a preformed party, like how the loot rules setting works. But anything that used via DF gets set to the standard like I explained above. Will there still be abuse? Probably, however you don't really have an excuse if it's a number SE at least expects players to be able to reach.