The number doesn't include irregular forces, including foreign mercenaries, destroyed by the Russians. Brian Berletic at The New Atlas, who must be getting tired of repeating himself, has the details in his update today on the war:
The kicker, which The Duran's Alexander Mercouris unearthed the other day, is that it looks as if U.S. intel learned that the Russians were withdrawing slowly, so as not to attract attention, from Kharkov, and then devised an attack that would make it look as if the Ukrainians drove them out of Kharkov. The cost to Ukrainian troops for this PR victory was absolutely horrific.
A cynic would ask what other bright ideas the Biden White House has for looking good in the run-up to November midterm elections in the USA. With just a little more planning, they can get the Russians to wipe out what's left of Ukraine's military.