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Quick question - where do you measure the kroxigor charge range from? Is it from the kroxigor themselves or the edge of the skink skirmish screen?
You only use the skinks for 'stand and shoot' distance determination.
So if the skinks are at 5" of the enemy unit than the kroxigor, who are standing at 10" for example, can charge through the skinks but the enemy unit can't use the 'stand & shoot' rule. As you measure from the skinks front as this is where they emerge.