[Mobhack]

Red v Ukraine in 2014/5? that gives battles in in either of Ukraine or Byelorussia). As a quick test run in the battle generator would tell you.

So - if you want to treat Byelorussia as 'rebels' then that may work for you. And you can always edit the Red OOB to add in kit you think the rebels should have from the Russian OOB.