SK2 has one German 50mm MTR, the other one this far is in SK3. So if there is ever a scenario with two such MTR.
SK2 is the only product with British 6-4-8/3-3-8 MMC, a British 9-1, a British MTR(a) 60* M2. Also if you don't have Elst it is the only product with the British 51mm MTR.
Also, it has Italian 3-4-7/1-3-7 MMC, not it an other product.
The only one with Allied Minor LMG.
So there are a few non-5/8" counters unique to SK2.