Instead of Progression i would write "first world/continent" kills.

Party A is doing 6100 dps with team ilvl media: 195 ilvl

Party B is doing 5800 dps with team ilvl media: 202 ilvl

Something is going wrong in Party B. Having a pld instead a drk don't make a 300 dps lost to get the kill.
- One or a few dps is not pulling their weights
- One healer or both healers are not dpsing.
- Tanks are more focused to don't die than stance dance.