Either of the Lati twins would probably be better in Goodra's place on that particular team, though Terrakion would still be faster, and stuff either of them with a Stone Edge. I understand that my team is not the best. I'm honestly just here to have a good time. ...And pass judgment on a whole slew of Pokémon, some of which aren't even given the time of day. (If you're doubtful... I'm going to be willingly use Qwilfish. Actually. I expect to be let down. The analysis for that is coming later...)Have you considered using a Soul Dew Latias (or Latios) in it's place? Similar bulk, higher power STABs, larger movepool including reliable recovery, more versatility with Healing Wish/Defog etc (not that you have to use those), sort of checks Pdon, and Psychic's weaknesses aren't that right now notable, outside of Pidgeotite Gengar. Just thought your team seemed a little vulnerable to ground types. This also checks Keldeo way better.
A few last notes on Mew before I sign off today... It's hard to use. You see so many more Mews that do nothing or just set up rocks and die, than those that are extremely effective. (To be fair.. that happens with Deoxys-S too... Just Psycho Boost that Gengar in the face already!) But Mew... is special. There is not one mon that truly has it beat, and it can act as a lure for ANYTHING. (okay, maybe not unbanned Genesect, but still...) Ho-oh? Stone Edge that bird away. Zygarde? Have fun with special Aggronite sets. Primal Groudon? Pidgeotite sets refuse to back down from the beast. (And Physical ones can pack Earthquake, too) The key to beating Mew is quickly diffusing what it's doing, and make the appropriate response. Blue Orb Scizor is (usually) a good bet for any physical sets. Special sets usually rely on what it's doing, though Blissey stops anything lacking Mold Breaker.
Your mileage will vary with Mew, and it really depends on how snug you fit it into a team.