I'd consider whether you aren't better off taking predators than the first and third havoc squads. You could swap out both of those havoc squads for a predator annihilator and an auto/las pred and still afford to keep the rhino on the first squad, giving it back to one of the noise marine units.
The las/las/auto/auto squad has more firepower than an auto/las predator but also comes to twenty more points. A predator annihilator is 15 points more expensive than the plasma/autocannon unit but almost matches the plasma guns for number of AP2 hits (2.668 plasma vs 2.22 lascannon). At range the lascannons are clearly better than the autocannons, within plasma range it's going to be situational depending on what you're shooting. Ignoring gets hot, the plasmas are better for T5 and under, the lascannons better for T6+, vehicles and multi wound models you can ID
With decisions like this (because I don't mind the havoc squads) I'd consider whether and how often) the difference could be the difference between winning and losing. I reckon with the predators' potential to start destroying stuff straight away it really could make a big difference.
To be fair the potential for the two plasma guns to roll up on side armour is worth mentioning, but that's less likely to happen if you are sitting back early to use the autocannons