Yes I think the IEI is learning to be more firm when he's dealing with difficult people there, which is part of his self-growth.
Department A is his own department and the supervisors there are very protective of him (SEEs come to aid whenever they see people in need of Se help, and this IEI is good at asking Se help that arouse sympathy). Department B has some overlap with department A, and is ordering him to do some work for them, which department A supervisors don't like. Between the SEE supervisors' creative Fi and IEI's creative Fe, this is interpreted as department B managers not respecting boundaries (SEE supervisors) or taking advantage of the workers (IEI).
After hearing the story my interpretation is department B managers are used to department A workers doing scrap work for them in the past, and simply continued to do so. They are also used to having a very macho/harsh way of giving orders, that gives people the impression that they are not being respectful. If I were the IEI I would 1) just like him, consult with department A supervisors and refuse department B work with legit reasons, 2) do not take offense of department B manager's harsh tones, but fake high Se with him to blend in, and 3) if I can influence the problem solving part to resolve the department conflicts I'd do it, but if I can't I'll accept that it's something out of my control and move on.
The IEI is doing 1) but not 2) and 3) because he thinks the department B's managers need to change. I feel he cares more about changing their attitudes than reducing conflicts and problem solving. The SEE supervisors from department A are also not doing anything to reduce the conflicts, partly because of their history, partly (I'm guessing) because this IEE has the image of a perfect victim, and putting him on the forefront would make department A has the moral high ground.
The high emotional tension he showed frustrated me and I wanted to reduce it. However after writing this post I'm thinking maybe treating this as an ethical issue (rather than resource problem solving) has its merit. Using a Te problem solving way would reduce emotional tensions, but would do nothing to change the department B manager's harsh/demanding way of communication, which is scaring some young/new workers
. Using the moral/ethical approach might be more effective to force them to change their attitudes?