Ranged troops are very important components in every attack. The most famous ranged troops in every clasher at the Clash of Clans are the Archers. Although they become vulnerable as the level of Town Hall progresses, Archers' role in the entire COC experience is inevitable.
Like Archers, ranged troops are those Army that can attack from a distance including Wizards. Executing your attack while understanding the proper placement of ranged troops can spell the difference between winning and losing you Clash of Clan battle.
Ranged troops are best used as support to tank troops such as Giants. It is often best to deploy ranged troops behind them. But this does not mean that you can't deploy them early.
Few Archers can be deployed early to clean up the structures between the drop off point and the walls. This is the best way to manoeuvre your Giants to the nearest target wall as they would rather walk and destroy towards other unguarded attack structure than bombard the walls for entry.
Another big advantage of ranged troops are their ability to attack structures behind walls without having to destroy the wall. They are much faster too in post-attack clean up. But ranged troop are not only good as pre- or post-attack Army. Understanding their range can make a difference in your attacks. The range has always to be within the building location, not just "touching"
Archers has 3.5 tile range, Wizard and Bowler have 3 while Heroes like the Queen has 5 and Grand Warden has 7. It is important to remember that Wizards and Bowlers target everything with less than two tiles distance from the wall while Archers hit structures that have two tiles, or less, to the wall. This is because a line of wall add some extra tiles.Watch how the Ranged Troops are being used effectively here: