That they used similar weapons does not make them the same at all. Reading the memoirs of men who participated in both, they always stress how very different they were.
WWI was a war of position. Attacks were prepared in advance, on enemy who were settled, often in trenches. The RCW was a war of movement and improvisation. Troops usually operated independently, often with only the most sketchy operational planning.
Even the Whites in the RCW were haphazardly commanded, and it got worse with the other armies. WWI units largely obeyed orders, for a start. In WWI you should assume an attack by units across the front would be co-ordinated, whereas for the RCW you should assume the exact opposite. A WWI army might have synchronised watches to ensure an attack was done to plan. The Russians just waited till they heard some shooting and played it by ear.
WWI rules assume effective indirect artillery fire, with large amounts of ammunition by trained officers. RCW had almost entirely firing in open field, with limited ammunition and officers who often were not well trained. If your rules make it an advantage to be firing from the rear, as it was in WWI, then they will give a completely wrong feel to the RCW.
WWI rules will have conscript infantry. That's your starting point for RCW, and mostly it should go down from there. Unless you read about it, you don't really get an idea just how trash much of the infantry was, both in morale and combat ability. Early in the war White infantry sometimes forced Reds out of covered positions in villages just by walking up to them -- while not taking cover and without shooting. I can't imagine any WWI rules would ever allow for a unit to walk on up to a defended village and win.
The amount of rifle power out of an RCW unit, even a good one, should be less than half of a WWI one. That leads to units fighting at much shorter ranges. It was a matter of willpower who won, not shooting.
Depending on the fronts, the use of cavalry is utterly different. RCW cavalry should be able to frontally charge an isolated infantry unit and defeat it, at least some of the time. It should absolutely dominate the battlefield if present in any quantity. (This is often a matter of making sure that any RCW battlefield has low troop density, rather than rules, to be fair.)
RCW units in trouble will rout. Not retreat fighting. They will not reform (in time for a table top battle).
WWI units would take a bombardment for hours on end, days even, from huge batteries. RCW units would flee after 10 minutes from a couple of guns.
Then there is the use of tachankas and armoured trains, which always need bolting on to WWI rules.
Some of 1914 was open. There were a couple of assaults in the RCW that resembled WWI. So there are situations which cross over, but they were very much not the norm.
I also don't get the point. You already play WWI. What do you gain by playing the RCW as if it were WWI?
adds a machinegun platoon to his WWI Brits.
