Both are doable for me, but had to re-roll the whole map once (refresh the browser page) due to some really really F* up RnG spawn on enemy side.
Of course, both my "4-5" whatever, were 4*. I dont know the odds on these event random characters/emblems, but I doubt its 50/50. Never got a 5* out of it so far. Will see after this event is done and over with, if there will be one finally or not.