It was generally acknowledged that the Russias practiced war of attrition and gaining ground little by little to avoid heavy casualties, thus using artilleries air strikes to neutralised enemy locations. Meanwhile, in recent UA advanced in Kharkiv and Lyman, use of numerical number of troops and armoured vehicles were obvious and witness by many videos. The UA used more than 3-1 ratio in above advance/attack. I eliminate the Kharkiv front as there were no battle.
You are asking reliability? Western support media or China? Reports are either by Russian or Ukrainian side, so read both side with pain of salt at digest both.
Following is Zalensky admission of. casualties (prior to UA counter offensive)
From Austrian strategist , huge losses of UA forces in many bridgeheads .