The su35 is already in GAME…well not technically but it kinda is…
When the SU30SM2 was added to the game i thought well daaamn the su35 aint far off if this is being added when they are basically almost identical in everything betweeen them
ROLES DIFFERENCES
The su30sm2 is a twin seater multirole “super flanker”.Its roles includes maritime strikes , air superiority , ground strikes and long range interception.While the su35s(single sitter) role is air superiority and long range interception.
WEAPON DIFFERENCES
https://zhuanlan.zhihu.com/p/541787547
The site above states the su30sm2 is capable of carrying the r77m …which i think is possibly since the su30sm2 is a plane that comes after the su35 in production.
both flankers share the following weapon systems
For air to AIR
R77M, R77-1, R73, R73M, R74 R37M both flankers have 12 hardpoints
Also found a source claimng the su35 can field the Ks-172 missile, nothing on the su30sm2 so probably the only difference
Su-35BM (Bolshaya Modernizatsiya - Big Modernization)
ANTI SHIP
On the su30sm2 Kh-31A, Kh-35
on the su35 Kh-31A, Kh-35, Kh-59MK, PJ-10 BrahMos, 3M55 Onyx
GROUND ATTACK
For ground strikes i have found the both use the exact same weaponry including the modular KH38 weapon system(modular means the seeker can be swapped from laser to an ir one so technically the kh38mt exist for those who call it a Brochure missile depends what the customer asks for).Also a ukrainian site mentioned the possibility of su30sm2 being able to employ the Kh-47M2 Kinzhal hypersonic missiles
Belarus Receives Advanced Russian Su-30SM2 Fighters—What It Means for NATO — UNITED24 Media
PAYLOAD
Both flankers from what i have found are capable of carrying up to 8000kgs(for both flankers) and a takeoff weight of 34500kg on the su30sm2 and same for the su35
Su-35BM (Bolshaya Modernizatsiya - Big Modernization)
mitchellaerospacepower.org/weapons/su-35/
ENGINES
They are both powered by the advanced AL-41F-1S engine. The su35 despite sharing the same engines as the su30sm2 is faster at a reported mach 2.25 while the su30sm2 can get to about mach 2 due the the additional seat and the canards increasing the drag.
RADAR ,IRST AND MAWS
They both share the Irbis-E PESA and the OLS-35 irst systems .
For the maws i could not find anything on the su30sm2 but the su35 comes equipped with the I-222 Optical MAWS(uses 6 infrared and 2 laser sensors for 360° coverage)
FLIGHT SYSTEMS
The su35 uses the The KSU-35 flight system which seamlessly controls the aircraft’s control surfaces, engine thrust, and 3D thrust vectoring nozzles. The system incorporates automatic flight control modes, automatic obstacle collision avoidance, and can even assist with in-flight refueling, reducing pilot workload
KSU-35 INTEGRATED FLIGHT CONTROL SYSTEM
The su30sm2 i found this site which list the difference between the sm2 and the sm that states the sm2 uses a FBW system “UNIFIED” with the one on the su35
Su-30SM2 fighter – unification with Su-35S » Russian aviation
CONCLUSION
The two flankers are different but the differences are so little.Mainly the roles ,the anti ship weapons employed, the ks-172 anti AWACS and the MAWS if i have missed anything feel free to enlighten me.