From your link:
"
   In May, when Washington ordered 1,300 Stinger anti-air missiles to replace those sent to Ukraine, the chief executive of Raytheon, the defence company that makes them, replied: “It’s going to take us a little bit of time.”
"

So, I assume you mean "Russia to be so effective destroying anti-air missiles with it's own helicopters and jets"  

And yeah, typical manipulation from you: In your article there no word about destroying, only words that EU has small amount of weapons, so when they sent something to Ukraine, they need a lot of time to restock it.

This is main point of the article:
"
   The Ukraine war has exposed the skimpiness of western defence stockpiles — especially of unglamorous but crucial supplies such as artillery shells that have been the mainstay of fighting. Lack of production capacity, labour shortages and supply chain snafus — especially computer chips — mean long lead times to replenish them.
"

So yeah, in near future after EU will start normal amount of military production, you ll see how russian "regrouping" from Belgorod  

Especially since russian in unable to destroy any of this western systems (as i remember, they destroyed frew m777 and few m109)

Yep, here it is:
- 9 155mm M777A2 howitzer:
2 155mm M109A3GN: (1, damaged) (2, damaged)
 1 155mm AHS Krab:  (1, destroyed)

Bad result for the "second world's army"