Soulknives have features that offer some but not all of these things. In addition to features that do a whole lot else (which not only can give you an alternate solution to infiltration problems, but
also takes more pressure off other party member resources so that your teammates have more room to help fill in some more of your gaps).
For example,
- They can significantly boost checks to create disguises and forgeries for their allies in addition to themselves, using the psi-die.
- They can significantly boost checks to know or discover information, using the psi-die. They can also use a telepathic link to someone who isn't present, who may know or be able to look up or divine information.
- They can use telepathy, which is helpful for passing yourself off as a number of exotic creatures (such as succubi). It is also extremely helpful for coordinating schemes with your team in general.
All of the above is just part of the level 3 feature.