Not sure if I would go with one of the Legend balls or the Black Widow Gold to go underneath a Scandal Pearl. I know Hammer puts them in the line below and their covers are a bit weaker but the cores are stronger, and more often than not I've seen the strength differences between the two be a wash. Hammer is one of the more popular brands in my area too so I've witnessed quite a few instances for this particular scenario.
Now the Phobia could be a fairly natural step down. I'm not sure if it would be enough of one though. Personal preference plays a big role here and to me that's just too close to the Scandal Pearl. It handles less oil and gets down the lane farther with more backend, but personally for me by the time adjusting my line/release isn't enough to keep a ball in play then a minor step down isn't going to cut it either.
So I would go for something two lines below the Scandal Pearl. And you're probably going to want something polished. Balling down from polished pearl to surface usually isn't great, although it really depends on how the shot breaks down too. Still, in general terms I would just go from polish to polish or something with fairly high grit surface.
And that leaves... the Rebel? It's definitely a step down, and still a really smooth and predictable symmetrical motion. To me that makes a lot of sense. You could go with a Diesel or Rebel Solid too (both polished or surface brought up) but I like the original Rebel.
Obviously this is all just my (lengthy) opinion, so take it with a grain of salt. You know your own game and which types of balls you can work with better than anybody else. Well, hopefully.
