  In this paper estimates on the ground state energy of Fr\"ohlich $N$-polarons
in electromagnetic fields in the strong coupling limit, $\alpha\to\infty$, are
derived. It is shown that the ground state energy is given by $\alpha^2$
multiplied by the minimal energy of the corresponding Pekar-Tomasevich
functional for $N$ particles, up to an error term of order $\alpha^{42/23}N^3$.
The potentials $A,V$ are suitably rescaled in $\alpha$. As a corollary, binding
of $N$-polarons for strong magnetic fields for large coupling constants is
established.
