Help with Logs Comparison

[Howlingstar]

Hey all,

so i've not long come back to the game and was trying out glacial spike.
I seem to be fluctuating a bit with my dps quite a bit.

Was hoping i could get some help comparing logs to someone with a higher percentile for Goroth as a base to figure out where/how i can improve.
My logs:
https://www.warcraftlogs.com/reports/A3 ... &source=12" target="_blank

comparison:
https://www.warcraftlogs.com/reports/bk ... &source=20" target="_blank

From what i can tell, looks like the other mage gets a third TW/BL which will make some difference. Also the glacial spike average hit seems to be quite a bit higher as well as only 1 more cast. Is it due to the massive difference in mastery?
I use askmrrobot and simc/raidbots to sim my gear and get stat weights so im not sure why i'm so far behind!
My armoury for reference though i've equipped a few upgrades since the logs
https://worldofwarcraft.com/en-gb/chara ... owlingstar" target="_blank