My dad is looking for a step down from his arson pearl when the lanes are just a bit too dry. He wants something that is long and strong. He throws 14-15 mph at the speed sensor with average hand. What are peoples opinions on these two balls? Any other suggestions?

The Tribal is too close to the Arson pearl, and it may even appear to be a step up because the Arson pearl is a smoother pearl.  The Tribal is very skid/snap, so again, it may appear to hook more.  The 400A is also fairly angular, though I'd say the Tribal is more consistent, or not as wet/dry sensitive due to the coverstock.  It's still going to be sensitive, but it has a bit more traction in oil than the 400A which makes it more controllable and predictable.  Between those two, the Tribal is the clear choice for me.