Algorithm for optimal rule-based arrangements?
As @Steven wrote, this problem is NP-hard. However that doesn't mean that you can't solve the problem for small instances.

You can solve such a problem by simply iterating over all $n!$ different permutations, and checking each if any of the arrangements is allowed and how good it is. This has complexity $O(n \cdot n!)$.

Much faster (but still exponential complexity) will be a variation to the Bellman–Held–Karp algorithm. Compute for each pair $(V, v)$ with $V$ being a subset of all vegetables and and $v \in V$, if it is possible to arrange the vegetables $V$ in a way such that $v$ is the last one and what it's best value is. You can define a recursive formula for this function, and apply dynamic programming, like in the BHK algorithm. That should run in $O(n^2 \cdot 2^n)$.