Some of that is a locality issue. Due to a mix of bad planning and Ukraine resisting rather more effectively than expected, Russian forces don't have enough equ

Some of that is a locality issue. Due to a mix of bad planning and Ukraine resisting rather more effectively than expected, Russian forces don't have enough equipment near the front lines so are falling back on what they can find for now. There is better equipment available elsewhere, but Russia is fairly large and getting that reinforcing equipment from one part to another is not an instantaneous process. I could be wrong of course. This isn't the first time I've heard the figure, but 75% seems rather a lot to have dedicated to this action at the outset. Do you have any reference for that figure?