I have lots of questions about when is the best time to use Hog Rider in Clash of Clans. Well, in my humble opinion, Hog Riders is one of the most useful troops in game, especially at Town Hall 8 and Town Hall 9. You will not want to use Hogs at Town Hall 7 at all since Hogs level 1 and 2 are very very weak, any Archer Tower, Wizard Tower and especially the Giant Bomb can wipe them out very easily.
If you want to attack a TH9 War Base in Clan War, you definitely should use Hog at least level 4, they are significantly much better than Hog level 3 and always can give you an easy 3 star win in both farming or Clan Wars. If you still don’t have level 4 of them in the Barrack, upgrade them right now, upgrade them as soon as possible!
Come with Golems and Wizards, they can dominate any Town Hall 9 War Base or even weak Town Hall 10. Also, the HogiBarch strategy is also one of the best farming strategy right now and of course you can’t use it If you don’t have a decent level of troops. It’s not just about the HP of your troops, it’s also about the damage they can deal. They always can take down a Wizard Tower before they even hit them 1 hit. It’s extremely important to care about your Hog from now on.