The first article you posted is about the battle of Ilovaysk where Pro-Kiev volunteer paramilitary units were surrounded and routed by Oplot and Vostok (Donbass one not Chechen one) The encirclement occurred because the Prykarpattia BN whom (according to the Kiev investigation - take it for what it is worth) in one month due to casualties and desertion whet from a strength of 4000 (I find that a quite liberal estimate) to a mere 300 at the time of the battle, "on their own initiative retreated from the battle" allowing the units in Ilovaysk to be encircled. The Kiev inquiry solely put the blame of the defeat on the Prykarpattia unit's unauthorized retreat, but the prosecutor declined to press any charges.
The second article mentions people who were discredited later when their lists of Russian 200s(KIAs) included 8 year old football club rosters from lower level leagues among other things, showing how .
The problem with trying to follow this war is not only its complexity (it is not a simple good guys - bad guys scenario some outlets try to communicate) but also that nobody involved can be trusted, at least not 100%. The idea put forward that the war in Donbass is a completely Russian (as in Russian government) orchestrated, controlled, armed, manned, and supported is ludicrous. The idea that there is no complicity from the Russian government or at least agencies/agents of that government is just as ludicrous.