Heracross does not need to run Scarf, although Scarf is its most common set. Crobat is certainly viable, although it's not near the top of the usage charts it's a fine Pokemon. Linoone is dead in UU at least until the release of Salac Berry. Team preview also severely hurts what is otherwise a surprise strategy. Maybe in RU it would have a chance.
About Hydration Lapras, I haven't tried it but I'm skeptical because it has a lot of easily exploited weaknesses. You have to put up rain, and then you have to set up Curse or Dragon Dance or whatever. Requiring two turns of setup is not good. Lapras is also part-Ice and therefore inherits all the weaknesses that come with it, including important weaknesses to SR and Close Combat.
About Hydration Lapras, I haven't tried it but I'm skeptical because it has a lot of easily exploited weaknesses. You have to put up rain, and then you have to set up Curse or Dragon Dance or whatever. Requiring two turns of setup is not good. Lapras is also part-Ice and therefore inherits all the weaknesses that come with it, including important weaknesses to SR and Close Combat.