Assume that the paths may not cross and each man must move.
Label the vertices $1,2,\dots,n$ in clockwise order. Let the man at
vertex $i$ move to vertex $\pi(i)$, so $\pi$ is a permutation of
$1,2,\dots,n$. If we draw an arrow from vertex $i$ to $\pi(i)$, then
we get a disjoint union of noncrossing cycles of length $\geq
3$. We can obtain such cycles by choosing a noncrossing partition of
the vertices with no blocks of size 1 and 2, and then orienting the
boundary of the convex hull of each block in two ways. Thus in
Exercise 5.35(b) of Enumerative Combinatorics, vol. 2, we should set
$f(i)=2$ for $i\geq 3$ and $f(1)=f(2)=0$. If the desired answer is
$h(n)$, then by this exercise we have
$$ x+\sum_{n\geq 1}h(n)x^{n+1} = \left( \frac{x}{1+2\sum_{n\geq 3}
x^n}\right)^{\langle -1\rangle} $$
$$ = \left( \frac{x(1-x)}{(1+x)(1-2x+2x^2)}\right)^{\langle
-1\rangle}, $$
where $\langle -1\rangle$ denotes compositional inverse.
If a man is allowed to stand still, replace $1+2\sum_{n\geq 3}x^n$ by
$1+x+2\sum_{n\geq 3}x^n$.
Possibly you can get some kind of explicit formula for $f(n)$ out of
this, but it will be messy.