Below is the orbat for the Russians at Debe Wielkie:
Infantry:
Regts. 93 [Brzeski], 94 [Bialosotcki], 96 [Wilenski], 99 [Podolski], 100 [Zytomierski].
Rifle regts. 47, 48, 49, 50
Cavalry:
Uhlans: 23rd [Litewski], 24 [Wolynski]
Mtd. Rifles: 1 regt.
The army commander was Rosen with Gejsmar commanding the units that fought at Debe Wielki. From the map I have, it looks like the area was covered with hills and forests but the fighting appears to have taken place in a fielded area.
On the right flank was 1 batt. of the 50th Rifles, along with the 48th Rifles and 4 guns; then 3 batts. of the Bialostock and 3 batts of Brzeski with 8 guns; then the Litewski uhlans, with the 3 sqs. of the Tyraspolski Mtd. Jagers on the far wing. Also, a batt. of Brzeski and 2 guns stood to the left of the village of Debe [basically guarding the road and acting as an advanced guard]. The Cossacks were at first placed on the left flank but when the action started 'dashed' across the battlefield to the right to attack the Polish infantry.
Gejsmar had about 8,000 infantry and around 2,000 cavalry.