I'm trying to tackle the following problem: given two graphs $A$ and $B$, if there exists a graph $D$ such that $\hom(A, D) > \hom(B, D)$ (i.e. there is more homomorphisms from $A$ to $D$ than from $B$ to $D$), then for any $c > 0$ there is a graph $D_c$ such that $\hom(A, D_c) > c\cdot\hom(B, D_c)$.
The motivation for this comes from the query containment problem for the bag (multiset) semantics, whose decidability is an open problem. The antecedent of the implication is exactly the fact that $A$ is not contained in $B$ as conjunctive queries. The problem could be colloquially described with if ever $A$ is bigger than $B$, then we can explode $A$ relatively to $B$, hence the title.
I don't know if it is true in general, however, for any two $A$ and $B$ I could've thought, it is true. Also, there're some cases, where the problem can be easily proven, e.g. when $A$ has more vertices than $B$, or when there's no homomorphism from $B$ to $A$.
Do you know a solution to this problem? Or a counter-example? Or maybe any paper that may relate?