To be fair, Hippowdon and Tyranitar are by far the best weather inducers outside of their Ability.
				
			Ground Type Viable and Weak to Grass: 5Grass is resisted by a large number of types and would functionally nerf water alone in OU. Most of the viable OU grounds have a grass-resistant secondary typing, and rock isn't succeeding in OU anytime soon regardless. It could help.
Small nitpick: none of Kyogre's checks are particularly affected by grass (read Latias, Arceus-Grass, and Palkia). If anything, it and Groudon would become easier to check.
Defog actually remove entry hazards on doubles/triples as you can aim it to your partner, so, yes, it just need an small improvement to being aplied on singles as well, but I could rather add a "block" of hazards for at least 3 turns, because all it's users are flyers, so, they're already weak to SR, so, they need something to being at least similar to it's Rapid Spin friends (because your flying friend will not be able to switch-in too offen to remove them).
About the weathers, I don't think that buffing even more them is actually a good idea, there should be a balance between weather vs weather-less, but it can also be fixed making better abilities that are not dependant of weather, anyway.
How about this:
A move similar to Tailwind that gives +1 priority to all moves for 3 turns
An item that gives +1 priority to all moves
Another ability but this time it gives +1 priority to attacking moves
DISCUSS!!!!
Overpowered and overcentralizing.An item that gives +1 priority to all moves
Another ability but this time it gives +1 priority to attacking moves
One thing that we can all agree it's going to happen is the damn Beat Up+Justified combo nerf.
It's hands down the lowest risk-highest reward strategy in doubles, so I don't see that staying that way in Gen 6.
Also, how about a new choice item called Choice Hat that gives +1 priority to one move.
And can be stacked with Prankster.
Imagine something like Vaporeon with this....mmm
Making weather not permanent but limited to 5 turns like Rain Dance/Sunny Day themselves makes a lot of sense. At most, they could have it permanent only while the Drizzle/Drought/Sandstorm pokemon is out, and then 5 turns after that.
Also, how about a new choice item called Choice Hat that gives +1 priority to one move.
And can be stacked with Prankster.
Imagine something like Vaporeon with this....mmm