Wiktionary
arrangeable
a. That can be arranged (especially in a specified manner)
Usage examples of "arrangeable".
Popper (and he is far from alone) counts individuals and populations as being of the same logical (and existential) type, and thus arrangeable one above the other, as different "levels" on the same scale (such as, in his scheme, level 7 and level 8, or level 10 and level 11).