In the eternal domination game played on graphs, an attacker attacks a vertex at each turn and a team of guards must move a guard to the attacked vertex to defend it. The guards may only move to adjacent vertices on their turn. The goal is to determine the eternal domination number of a graph which is the minimum number of guards required to defend against an infinite sequence of attacks. This paper continues the study of the eternal domination game on strong grids $P n P m$. Cartesian grids have been vastly studied with tight bounds existing for small grids such as $k × n$ grids for $k ∈ {2, 3, 4, 5}$. It was recently proven that the eternal domination number of these grids in general is within an additive factor of $O(n + m)$ of their domination number which lower bounds the eternal domination number. Recently, Finbow et al. proved that the eternal domination number of strong grids is upper bounded by $nm 6 + O(n + m)$. There exists a gap still between the lower and upper bound as the domination number (current lower bound) of the strong grid is nm 9. We prove that, for all n, $m ∈ N *$ such that $m ≥ n$, $nm 9 + Ω(n + m) = γ ∞ all (P n P m) = nm 9 + O(m √ n)$.