Heavy Firing of Civilians in Donetsk Continues – HIMARS Rockets from US?

Alexander Mercouris suggests a few things in his evening video on the 21st of June in relation to the bombardment of Donetsk.
That it would appear that the American artillery is being used on Donetsk, not the front line.
That Donetsk, the oil rig, and Lithuania are being used as “distractions”.
That the Russians will stick with their objectives and when northern Donbass is achieved turn their attention to Donetsk.
That Russia is still using an “expeditionary” force and that the soldiers are regularly rotated in and out. That much of the “street fighting” is done by the Donbass militia, not the Russian army.
A commenter has remarked that the area/city from which Ukraine is shelling Donetsk also has a large civilian population, so surrounding would be a safer strategy for the civilians than missiles.