British study find 42k Russian troops being rotated in E. Ukraine

Large-scale intervention in eastern Ukraine by regular Russian troops began last August, reaching a peak of 10,000 in December, and Moscow has been struggling to maintain operations on such a scale and intensity, according to a report.

. . . the Rusi report says that a total of 42,000 Russian troops from 117 combat and combat-support units have been involved, either being rotated in and out of the front lines in Ukraine or pouring artillery fire from inside Russia.