The new dark troop, the bowler is a very unique troop, so I imagine it has unique strengths and weaknesses. What strengths and weaknesses does it have?
The bowler can target multiple buildings at once, which makes them ideal for funneling troops, as they can clear out larger areas at a time. However, they have relatively low hit points (higher than a wizard though) so they can't be left alone without something to distract the defenses for them. This funneling can be especially helpful against bases like the donut base which have a large ring around the townhall designed to circle the troops around the outer ring without targeting the townhall. Also if they are grouped together, they can be taken down fairly quickly if targeted by splash damage.
On defense, they can also be useful, as their attacks will bounce past the first troop they hit. Thus they can potentially hit the "back line" of troops, which generally consists of the higher damage dealers such as wizards or the Archer Queen, by bouncing the rocks off the "front line" of tanks. However, they do not have as high of damage as wizards so they will not be able to destroy high health troops as fast; nor can they target flying troops, so they will be much less helpful in defending against any air attack.