Ok it's late but I'm going to take a shot at this. Here's what I think the mixed attacker should look like:
name: Mixed Attacker
move 1: Blizzard
move 2: Wood Hammer / Giga Drain
move 3: Earthquake / Focus Punch
move 4: Ice Shard
item: Expert Belt
ability: Snow Warning
evs: 140 Atk / 220 SpA / 148 Spe
Wood Hammer is better than Grass Knot/Giga Drain. It has much higher base power (which means it does a shitton more to neutral switch-ins), it's stronger against Blastoise, and it 2HKOes CB Snorlax with Hail damage. The damage output is only slightly less against Suicune and Slowbro, but they cant beat you anyway. Focus Punch is a pretty good option if you opt to use Giga Drain instead of Wood Hammer, since it lets you OHKO Snorlax on the switch, and deal upwards of 70% to Umbreon. The EVs let you OHKO Flygon with Ice Shard and outspeed min Blastoise, with the remainder in Special Attack.
The subseeder should be using a spread of 248 HP / 252 SpD / 8 Spe with a Sassy nature and Wood Hammer slashed before Calm nature and Giga Drain. It needs full investment in Special Defense so it can tank Raikou, Shaymin, Cofag, and [insert Bulky Water] more effectively. Wood Hammer should be the primary choice so you can actually beat CM Raikou.
As for the CB set, the fourth slot should just be filled with Ice Punch since Focus punch has redundant coverage with Earthquake and it doesn't prevent you from being walled by Bronzong at all. Its EVs should be 54 Hp / 252 Atk / 204 Spe to get the jump on minimum speed base 85's.