So you get a new Codex and switch to the second oldest one...
I personally think that the Fast Attack choices are generally the strongest in most Codexes and Chaos is no exception. (Side note - it should be Codices, like matrices, but GW has to be special...) Chaos Bike Squads and Raptor Squads would fit the list nicely as they're fast close combat units which can take multiple special weapons regardless of size. This primarily means that they can Assault at the same time as the Berserkers which means your opponent will only have 2 Land Raiders to shoot at... [Insert evil laugh here]
I guess what I'm getting at is if you drop the three Rhino squads and instead take three bulked out MoK Raptor/Bike Squads each with Power Weapon, Meltabomb, Close Combat Weapons and Special Weapons, you might find your control of the board better...
My tactic would be to drive the Land Raiders into the enemy along one flank using terrain to shield, whilst hiding your fast units as much as possible. Then everything jumps out in one turn, Berserkers tying up the two biggest squads and the Raptors and Bikes Meltering three different vehicles to death then charging in as well. You can mess with the enemy by using turbo boost to faint where you're going to hit if you're clever. Disclaimer #1: I'm not clever.
Since I don't have the codex:
Are naked Chosen more cost effective than Berserkers?
Would a Dark Apostle be better than a Chaos Lord?
Have you considered any Daemons?
Also who is going to hold rear objectives, unless you're being really brave and putting them all in your opponents deployment zone? Disclaimer #2: I'm not brave.
Hope this helps...
Slick Samos