Ka 50 (and ka-52) have some stealth compared to other helicopters in RL., they have reduced heat radius (Engine exhaust heat screens reduce the thermal signature of the helicopter and flare dispensers protect the helicopter against heatseeking missiles.) they are fitted with radar warning receiver and they have reduced NOISE, electronic warfare system and chaff and flare dispenser, so basically they are harder to spot/shot.
But this is correctly represented in the game as medium stealth for Ka-50/52 and good stealth for Tiger (everything what Ka 50/52 has + fully composite and Radar cross-section (RCS) reductions, so basically better stealth)
But what really must be represented in this game (compared to Tiger HAP/HAD) is greater maneuverability of Ka50/52.
"The coaxial-rotor configuration results in moments of inertia values relative to vertical and lateral axes being between 1.5 to 2 times less than the values found in conventionally designed combat single rotor helicopters with tail rotors. Absence of the tail rotor enables the helicopter to perform flat turns within the entire flight speed range. A maximum vertical g-load of 3.5 combined with low moments of inertia give the Ka-50 a high level of agility and maneuverability."
It must be more agile: faster turn radius, faster take off, landing, start/stop of the fly, if we will have this, then it will be ok at their price.
Also as I said before, Ka50/52 must be more accurate with their cannon (because of mounting, helicopters with guns at their nose cant be so accurate because of vibration, meanwhile Ka50/52 gun is mounted at the midle-side, it's so accurate what sometimes it's even called sniper, and we don's see this in game, in RL it's easy to kill IFV from long distance with just few shots, meanwhile in game it's gun is crappy).