You're lacking Stealth Rock, which is huge for any team. Tyranitar won't find itself using Earthquake very often, since it's really only useful for Heatran (you've got Stone Edge, Gastrodon and Latias for him), so consider dropping it for SR. This'll help Gastro take on Thundurus better, since it needs the 25% damage SR will bring in order to nab a 2HKO.
The other change I'd try out is Roar over Psycho Shift on Latias. Blissey will oustall you anyways and with entry hazards, a well-timed Roar can weaken Latias's grounded counters (Jirachi, Scizor, Tyranitar) well enough so that she can sweep easily late-game. This'll also provide a solid check to CM Reuniclus / Virizion - simply boost up alongside them and then phaze them out, leaving your opponent staring at a +6 Latias. Hope I helped, good luck!