Tarnished Sentinel medallion

[Dakodai]

Heya,

So is Tarnished Sentinel Medallion really as godlike for Arcane as the sims say it is? I just simmed a 915 socketed version replacing my 905 whispers, resulting in a dps loss, but on the trinket spreadsheet is has nearly double the whispers value. My other trinket in the setup was a 930 tome of unraveling sanity, using kilt+soul with t20 2pc, at ilvl 925 total.

is the sheet wrong, or the sims? Am I a massive idiot?

It's gotta be one of those three.