Well Tyranitar is base 61 speed and Hippowdon is base 47. And on Smogon it says this;
Tyranitar has a vast movepool, but many of its moves are not viable in VGC 2012.
Hippowdon does not have a great offensive movepool, and its great support movepool is admittedly more useful in singles than doubles.
In Singles Tyranitar can be fixed with a choice scarf, and they can both run more supportive sets, but the problem is in VGC and Doubles most of their utility comes from their Abilities and good attack. Obviously, due to their low speed and the fact it is doubles, if you want to run offensive with them the most viable option is in a Trick room. Additionally;
Trick Room is an effect that changes massively from singles to doubles. In singles, it's an underwhelming effect that works mainly based on the element of surprise most of the time, while in doubles, it becomes one of the most feared global effects, with an arsenal of Pokemon ready to abuse it. Pokemon that are good, like Conkeldurr, become great, and some of the not-so-famous threats like Carracosta get their chance to shine. All in all, a very dangerous global effect that usually acts as an "anti-weather" effect by turning the tables on fast sweepers.
Trick room is alot more effective since you can have 2 Pokemon at the same time abusing it, and with at least one being able to set it up, unlike Singles where you need to switch out, or have the abuser know it, using up a moveslot.
I have no idea what I just typed up xD. Anyway so yeah,you can go around probably with more single based movesets, and support ones, but they probably won't work as well in Doubles so I'd say Trick Room is the best way to abuse them.