Very well let us look at another Russian ship, a frigate class the Grigorovich, now the frigate is about 400 tons heavier thats not huge in ship mass so they are fairly similar sized ships.
one is 3600ish the other is about 4k even fully load.
I am copy to copy and past their weapons exactly so no one can say "American BS"
for the frigate
1 × 100 mm A-190 Arsenal naval gun
1 × 8 UKSK 3S14 VLS cells for Kalibr and Oniks and Zircon
2 × 12 3S90M Shtil-1 VLS cells
2 × Kashtan CIWS
8 × Igla-1 (SA-16)
2 × 2 533 mm torpedo tubes
1 × RBU-6000 rocket launcher
1 Chopper (also has ASW ability)
for the "corvette"
1 × 100 mm A-190
2 × 30 mm AK-630M CIWS
2 × 14.5 mm MTPU machine guns
Redut medium-range air defense system (2 × 8 cells)
Paket-NK anti-torpedo/anti-submarine torpedoes (provided by choppers only)
Kalibers, it can mount these in containers only but then it must sacrifice things to mount them
OR we can look at their problem frigate
1 × 130mm Amethyst/Arsenal A-192M naval gun with rate of fire of 45 rds per minute 
16 (2 ×
UKSK VLS cells fitted with P-800 Oniks (SS-N-26) and/or Kalibr missile system (SS-N-27)
32 (4 ×
Redut VLS cells housing 9M96, 9M96M, 9M96D/9M96DM(M2) family of missiles and/or quad-packed 9M100 short range missiles
2 × Palash CIWS
2 × 4 330mm torpedo tubes for Paket-NK anti-torpedo/anti-submarine torpedoes
2 × 14.5mm MTPU pedestal machine guns
Yes this frigate is about 1k tons heavier but again in terms of ship weight that isn't massive infact the Gorshkov's bema is only 4 meters longer then the Derk and it's length is only about 80ft longer then the Derk's. The only reason is weighs 1k more is because of howmuch they packed into it weapon wise.
Now both frigates out class the Derk in combat ability but the Derk outclasses them in the utility if offers the navy.