Barbarian is the first ever troop you get on Clash of Clans. Even though he won't be useful for higher lever town hall war attacks ( except distracting enemy clan castle troops ) can be used in multi player battle to earn lot of loots through Barch attack strategy (Barbarian+ archer). It doesn't mean you don't have to increase his level as his level decides your Barbarian kings Iron fist ability summoned barbarian's level.
Barch strategy for unlimited loot
How Barbarian works in clash of clans
Barbarian is programmed to choose his nearest building (both defenses and offenses). So his Pathing is looked like this after deploying him,
So if you want your barbarian to attack particular defense or offense you must funnel him through the defense or offense. So what is funneling? clearing any particular defense or offense which can drive your barbarian to any of the targets you want him to reach is funneling. So let's take the above barbarian path image and if we already cleared the second target (elixir drill) with some barbarians then the new barbarian's path will be like this,
So controlling troops is in our hand all we had to know is how to control them. Let's see you all with other troops mechanism! Clash on!
Hello, my name is Jack Sparrow. I'm a 50 year old self-employed Pirate from the Caribbean. 
