One tempo, and the library proves the window exists
Every archetype declares a tempo range, and the six in the default package overlap between 112 and 116 BPM, so the whole set is held at one number inside it. That is what lets a sweeper butt against an ID without a lurch. The overlap is checked when the library loads, so an edit that broke it stops the build rather than quietly shipping a package that no longer agrees with itself.