Hmm...
1) I haven't the faintest idea what "coy" is in relation to the military, but granatwerfer is a mortar.
2) Never heard of an acronym Pzlg? May be a typo.
3) Typically there is one light machine gun per platoon, or 3 squads (roughly 36 men). Heavy guns are a means of battalion support, and I believe one heavy MG is assigned to a company, or 3-4 platoons (100 men).
Hope this helps?
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