Answer
We can rank the arrangements according to the separation between the objects:
$2 \gt 1 \gt 3$
Work Step by Step
We can find an expression for the separation distance in each case:
(1) $d = \theta~r = (2\phi)(R) = 2~\phi~R$
(2) $d = \theta~r = (2\phi)(2R) = 4~\phi~R$
(3) $d = \theta~r = (\frac{\phi}{2})(\frac{R}{2}) = \frac{\phi~R}{4}$
We can rank the arrangements according to the separation between the objects:
$2 \gt 1 \gt 3$
