Lati@s has Grass Knot for Tyranitar. And the only reason I see them as Ubers is Soul Dew. They should be allowed in standard play, or at least tested when they don't have Soul Dew.
Assuming you don't switch into Surf/Grass Knot, TTar will win. To give you an idea, standard Careful Tyranitar (252 hp/216 sp.DEF) takes 39.3%-46.53% from surf, and 52.72%-62.13% from Grass Knot, from 252 Modest Specs Latios. Assuming we don't allow soul dew, lati@s is going to have trouble with ttar.
That said, again I see their nice stat layouts with no glaring weaknesses as quite impressive, especially with their movepool. Wow
I think Manaphy should be tested. It doesn't have a movepool like Mew, yet they have the same stats. It has common weakness to Electric and Grass, it doesn't have the greatest speed to sweep with Tail Glow. The only thing keeping it in Ubers is Kyogre's Rain? That shouldn't be enough.
As if we needed a bulky water type with the same speed as Salamence/Zapdos, better defensive tiers than swampert on both sides, and perfect coverage with energy ball.
That's not even getting to all the stuff tha manaphy is known for being broken for yet (hydration/heart swap/tail glow/etc.)
If you thought Jirachi/Celebi were good, try the same base stats with pure water, one of the most balanced and powerful typings both offensively and defensively in the whole game.
My gripe with manaphy is mostly that it is the bulky water to end all bulky water types, as if they weren't powerful and present enough.