I just noticed, vice-marshals can't step down, is it suppose to be like that?
I noticed the same last week and its part of a series of other fixes I'm working on with the step down process. In the meantime, just have the sponsor change the vice marshal.
Aye, Aye Captain
Make sure your army sponsor promote a new Vice Marshal. This is the only solution to a bug I opened previously for my character Brock who was Vice Marshal of 2 different Armies, even though he was only assigned to 1 Army. Cannot step down as somebody need to be promoted.