The problem with Freeze is really with Mab. Freezing an enemy on a 4 or 5 gem match is crazy powerful and should be limited to some extent. In fact, that probably goes for most match on 4-or-5 skills.
I propose two potential solutions:
Remove RNG from debuffs. Change Freeze from a singular status effect into levels of status. IE: Freeze 1 applies for a single turn. Non-stacking. Freeze 2 applies for 2 turns, etc. Immediately change Mab's freeze trait to a Freeze 1 trait. This has the side benefit of letting the player know when the status effect will go away.
Limit debuff based traits: LIMIT 1 PER TURN. That is, it doesn't matter if you get 100 4-matches or just a single 4-match, only one enemy is debuffed from your skill per turn. This prevents the utter bullshit of having your entire team stunned and frozen after a single defenders turn.
IMO the traits are the real issue. Debuffs are fine for troop skills but far too powerful for traits without some limit.
In the long run I think option 1 is better because this same idea could be applied to current and future troops such that there is a bit of differentiation between a Legendary troop that casts a level 4 freeze spell and a Common troop that freezes all enemies but only for a 1 or 2 rounds.