Those two trinkets (Phial of Putrefaction and Shadowgrasp Totem) can have pretty variable value depending on the assumptions that you make about the fight that you are doing.
If you are good at using the Shadowgrasp Totem when enemies are dying and you are doing pretty big pulls, it can be quite good. Feel free to use the customization options to multiply the value of this trinket if you find that you are consistently getting good use out of it (try starting with a value of 2.0 or 2.5). We added this feature specifically for cases like this where a “one size fits all” ranking isn’t really possible.
For the Phial of Putrefaction, it is also highly dependent on how many targets are in your pulls. If you are doing pulls that tend to be smaller, like 3-4 enemies, it’s not that great. If you are doing pulls with 5+ and are diligent about spreading the poison out to all the targets (target-switching every 5 sec), it can be quite good. Once again, try starting with a value of 2.0 or 2.5 and tweak it from there as you see fit.
Our default rankings I think are pretty good for the general player who doesn’t tailor their play around a specific trinket – you don’t need to do anything special to get full value out of it, and its value doesn’t depend heavily on the size of your pulls.
I can’t speak to how raidbots or bloodmallet rank these trinkets, but I don’t think that a single number can adequately represent them. Definitely customize it to your play situation if you find that you are getting good value from those trinkets.