I'm all for giving them a Westernized Horde government, maybe with reduced boni (25%?), but removing it altogether is just going to be bad.
Having thought on this idea, it wouldnt be a bad idea, although the 50% bonus to Force Limit/Manpower should probably remain as is as, they are not that large. Let me get a nice little chart for you.
Russia - Absolute Monarchy:
+10% Discipline
-1 Revolt Risk
+125% Manpower
+50% Land Force Limit
-50% Infantry Cost
-15% Core Creation
+10% Manpower Recovery
+10% Production Efficiency
+1 Colonists
Auto Explore next to Colonies
+0.5 Army Tradition
-10% Technology Cost
Timurids (These guys have the best of the horde NIs) + Steppe Horde:
+50% Manpower
+50% Land Force Limit
-50% Relations Decay
+25% Unit Power (Infantry/Cavalry/Artillery) in owned Plains and Desert Provinces
Pretender Revolts if at peace too long
Pretender takes over if regency happens
Succession Crisis on weak claimant inheriting throne
-25% Core Creation
+10% Army Morale Recover Speed
-2% Prestige Decay
+50% Religious Unity
+3 Heathen Tolerance
+20% Cavalry Power
-10% War Exhaustion Reduction Cost
-10% Land Attrition
-10% Stability Cost
+1 Monthly Prestige
+5% Discipline
As you can see, Russia can still outproduce Timurids due to +10% Production Efficiency and -50% Infantry Cost. Timurids significantly but not substantially outmatches them in quality, as while the Timurids has less Discipline, they also have a whopping +25% Power bonus, but this only applies on their territory in plains/desert terrain (which means Timurids loses their quality bonus if they launch an attack on Russia). While the Timurids have some nice bonuses, such as +50% Religious Unity, the Prestige bonuses, and Stability cost, it might be a bit difficult to argue that they are better than the -10% Tech cost and +0.5 Army Tradition that the Russians get.
That doesnt even count the hurdles Timurids has to go through in order to westernize. Especially since Westernization is easy for Russia since their St. Petersburg decision gives them a whopping +3 stability.
This is why removing Steppe Horde Government from Western hordes will absolutly kill them. Western tech Hordes will have nothing capable of stopping the Russian zerg as hordes are entirely dependant on their government and generic ideas for military bonuses.
CK2? I would understand if you would complain about non-Europeans in Vicky2, but in CKII you can easily defeat the Europeans if you play as Muslim or Tengri Pagan. Especially Mongols with their huge doomstacks are easy to play.
One word: Norse. Reformed Norse also keep most of the Norse bonuses while losing all of its penalties.