There is no need to have Jolteon and Electavire on the same team, regardless whether or not they're playing different roles. Salamence and Porygon-Z is a very effective offensive style alone, so I would keep them in the team as your main offense.
I feel that Jolteon's main recepitant for its Agility would be Electavire. Now I would replace one of these to remedy of some weaknesess still left in the team. But then when you think about it, without Jolteon, what's the point in Electavire? And vice-versa.
Well if you were to replace both, forgetting the Baton Pass strategy, then I would add Bronzong and Tentacruel. It gives you Toxic Spikes support, and the protection for it along with Stealth Rock and Spikes with the addition of Rapid Spin. It also counters Infernape (a threat to the team) aswell as being able to take hits hard. It's also a decent MixMence counter. Bronzong would then give you more resistances and a viable Mamoswine and Garchomp counter - or atleast it take the fall to a Fire Fang variant but with the support of Toxic Spikes it should fall soon after that. Hypnosis is always a great addition to any team, and you'll be able to give Blissey another move option should you add Stealth Rock on Bronzong. Both standard sets are fine and a Bronzong lead is always great.
Which brings me to advising Wish over Stealth Rock on Blissey because Bronzong is now providing the rocks. In theory, it will be able to heal Tentacruel and Bronzong to continue to counter threats, while Toxic Spikes eats them slowly.
Lum Berry on Salamence seems a little odd to me, and very situational indeed. I'd throw Life Orb (then adding Fire Blast / Flamethrower over Stone Edge), Leftovers or even Yache Berry.
I know it's the boring old standard way, but because you had a special and physical wall it only seemed fitting to patch up some loose ends of the team along with the Mixed Pokemon that are always a danger.
