The implementation of mortars is not trivial; we all saw that in game terms, they were highly effective in CMX1 - perfect for taking out MGs in woods, for example. I would expect to see the U.S. 60mm Mortar - both the M2(?) and the airborne M19(?) versions, the latter possibly being modelled like the current 51mm in British service.
While small mortar batteries can be simulated by/as off-map artillery, I don't know how often they were actually employed that way - as Geordie points out, they are used today for smoke screens at the platoon level (Canada still uses the U.S. M19 airborne mortar and some of our EIS is U.S. Army war dated - I've seen it in our stores) as well as HE, illum, etc. In game terms, the use of single weapons would probably be noticably absent, if not in historical terms, then certainly from the legions of CMX1 players who will be returning to CM:N hoping to find the gameplay has not appreciably been altered by the change in scale of the onscreen representation. Not having light or even medium mortars on the map would be a major shift.
It would be more usual to see 3-inch, 81mm and 8.1cm mortars of the British, Americans and Germans employed in platoons, and used as "off map" artillery, and their exclusion from direct representation would be less of a hardship in my opinion. But I think the lights definitely need to be in there. The Germans stopped using the 5cm midway through the way, calling it the "meatball thrower" but it was a real presence in British infantry platoons (the 51mm weapon seems not to have changed much since 1944) and in American infantry companies.
