Yes, GWSH II meets all your criteria, except I only put two 15mm figure on each stand, as I’m cheap:)
Manouvre units are regiments/brigades and formations are divisions. Rifles and LMGs shoot as far a you’d expect with a ground scale of 1″ to 80 yard. I’ve used them extensively for both trench and open warfare, in fact the trench warfare rules are some of the best I’ve ever come across and I shamelessly borrowed the pre-game bombardment mechnism for my own rules.
"Mistakes in the initial deployment cannot be rectified" - Helmuth von Moltke