Agreed, I really don't like the RNG based CC in a strategy game. I do like chilled -> frozen and shocked -> stunned progression and casters have always felt a bit more challenging to get good CC chains on, or at least forced you to use consumables in a clever way. Physical comps are insanely easy to just battering ram/battle stomp/chicken claw CC chain everything to death. Granted, it's not very hard with magic comps either. I like the progression based CC a lot, but CC chaining is a problem because hard CC that makes the enemy do nothing but skip their turn is a problem when it can be constantly reapplied. The way I see it the answer lies in a balance of the following
1) Applying CC is more difficult, but still not RNG based. This may mean an additional stage from shocked to stunned and soforth.
2) Enemies become resistant to hard CC after being affected by it once, perhaps granting them a round of immunity to stunned/frozen/knockdown. Perhaps ties this in with the perserverance skill to make it more appealing?