Battle Mages should have no problem since the SP for the 4 jobs are separated.
Well, you cannot allocate points into a higher job if there are unused points in the lower one.
For example, if you reset 5 points out of 2nd job, you'd have to put those 5 points back into 1st or 2nd before you could allocate more 3rd job points.
Spoiler!
Idea: Wait for a hot time event, they do one or 2 every 2-3 months.