This morning I played some mystery hero, and I had multiple games in row on defense where our starting lineup had no tank and no healer. The opposing team had balanced starting comp, so they relatively easily capped the initial point.
By the time we got a couple of healers, they would get 3 flankers to easily dispatch those (we didn’t have good anti-flanker at that point).
Eventually we would get tanks, without shield, so as you can guess the enemy would have a sniper.
It would be good if the “random hero selection” was made to be slightly less random (e.g. if there’s 0 of one category, double the odds of getting that, if there’s one, maybe 1.5x the odds of getting the under represented category).
Also for the starting comp, make sure there’s at least one of each category.
I think that will make mystery hero more balanced and therefore more fun to play.