That snapshot doesn’t have your great vault rewards in it, so I can’t reproduce exactly what you are seeing.
The Shadowgrasp Totem is one of those items that is very difficult to predict its value… it really depends on how good you are at using it just as targets are dying, and then how well the cooldown reduction lines up with the series of pulls that you are doing.
I encourage you to customize its value if you are able to make good use of it in the content that you do. To do that, on Best in Bags, go to the Customize tab, check Special Items, search for shadowgrasp totem (you can use the textbox above the list), then enter in a value greater than 1.0 to increase its value, e.g. 2.0 would double the estimated value of the on-use effect.
Also note that our trinket rankings factor in a reduction in value from using two on-use trinkets simultaneously (because most trinkets trigger a lockout on each other, so you can’t stack them in your highest damage windows). A straight ranked list of each trinket in isolation is not all that useful for most on-use trinkets.