Here’s a set of free wargames rules for operational level actions during WWII. Battalions are represented on a 2×2 base, and the entire thing is inspired, it seems, by Volley and Bayonet.
WWII
Krieg Ist Mist WWII Rules
Krieg Ist Mist is a set of free wargames rule for 6mm games set in WWII.