1 inch is still 50 paces for 15mm.
Artillery is artillery wether limbered or unlimbered.
Not all squadrons need be part of the same, or any, group. Such battalion groups are formed with each company facing in the same direction and in corner-corner and edge contact with another company. Groups may be formed of the companies of the same grenzer or jaeger battalion if and only if each is facing in the same direction and in corner-corner and edge contact with another member of the same group. Not all companies need be part of the same, or any, group. Other groups may, however, prevent an enemy from gaining an overlap.