Hmmm, this is interesting. Hadn't seen it reported before, but if true, makes it appear as if Russia wants to do things on the cheap in Eastern Ukraine:
link
"The Kremlin attempted to use large-scale military exercises to conceal its condition-setting on the Russia-Ukraine Border. The Kremlin capitalized on international focus on its scheduled Vostok-2018 military exercises to shift assets from Eastern and Central Russia to the Russia-Ukraine Border. The Ukrainian Defense Ministry reported that Russia transported artillery units from Eastern Russia to the Russia-Ukraine Border during Vostok-2018 from September 11 – 17. The Kremlin in recent weeks also reportedly shifted large numbers of T-62 tanks from Eastern Russia to the Russia-Ukraine Border.[2] Estimates of the transfer range from five hundred to one thousand tanks. The Kremlin may intend to assign some of this equipment to its proxy forces during large-scale snap military exercises that will occur in the Southern Military District through the end of October 2018".
I've even seen a JS-III tank put into service, but that was apparently a one-off, display vehicle.
Apparently, in the last four years or so of the conflict, Russia has sent lots of other more modern tanks into Eastern Ukraine, so now there are hundreds of them, instead of just scores of them, when the conflict first started to really heat up.
link
That's as of August, 2017, so is probably even higher today.
"Since fighting erupted in July 2014, the number of Russian tanks spotted by Ukrainian observers in Donetsk and Luhansk numbered 30, Ukraine's Media Crisis Center reported on Wednesday. Three years later, this figure has increased 20 times to 680".