Researchers under fire, I dont know what I am doing wrong

While doing research under fire in the Zaralek Cavern event I am getting different rewards for what feels like the same effort.

On my BM hunter I do the event from start to finish, dps and gather for all of the events and get an epic tier 4 reward in the end.

I do the same event on my resto Shaman, dps and gathering materials and outside healing. But when the event ends I get a common tier 2 reward.

Both characters are done outside of a party and do the event from start to finish. The only main difference I can see is that my Shaman does not have the same DPS output obviously.

I am trying to figure out what I am doing wrong to get such different reward results. Does this event have to be run as a DPS?

Is the character that is getting a lesser reward in a shard where fewer people are doing the event? The only purple bag I got, I had to join a full-size raid group. Every other time I do it with what seems like a decent-sized group in my shard, I get white or green bags. You have to really push to progress the phases in order to complete the objectives before the timer runs out for that phase.

It’s like the soup event in a sense that the shard has to be extremely active, but at least the boss does spawn whether you do all the objectives or not. Short answer, having more DPS could help in the end, but I feel like the reason is based more on the overall group progress. Resto shamans are pretty strong damage dealers, though!

I think this reward system is terrible and I don’t like the fact that they scale based on the shard activity (I get 10fps in the full-size raid groups in these events).

The number of people doing the event was pretty high as we destroyed everything pretty quick. Though I am playing on a heavily Horde populated server and I am Alliance so I could see my contribution as a solo player not counting as much.