But if you're using MBTI's no.
I think they both serve their purpose.
I actually like using both, to get more accurate 5-letter representation:
Those with "Jj" definitely regularly seem to be the most "Jish" of the types, and those with "Pp" definitely seem to the most "Pish".
And those with "Jp" or "Pj" tend to fall somewhere in between these other two groups.
And yes, I believe your function order in MBTI ought be the same as your function order in Socionics.
I don't care if the description sounds different from one system to the other, there's myriad reasons why that could be the case.
You don't magically switch from having FiNe be your foremost cognition style to NiFe -- that makes no sense.
They're both built off Jung, and, as such, the functions in each system should be pointing to the same underlying reality.
Perhaps the author(s) writing a description for Socionics just has a bit of different take on some functions, for whatever reason(s).
I could see aux Se making an ISFP much more quick to judge than the aux Ne of an INFP.