Yes, compounds have abrasives, and do a better job if you want the ball to read the mid-lane in my opinion. They will also, depending on how aggressive the abrasive, change (smooth out) the underlying grit to some degree.
Many polishes do give the ball length due to the slip agents, but that can be a double-edged-sword. I rarely use a polish due to over/under reaction. I prefer to smooth the surface more (2000, 3000, etc) then use the compound if I want the ball to push through the heads easily. For my spare ball, yes, polish. Hope this helps.