He is wrong though.
To put it into perspective: 53 is where FAL switches from 2-3 hk which is pretty close range. 123 is where SMR switches from 2-3hk which is med-long range. At 53 units EVO, Vector, Chicom are 5hk. Other SMGs are 4HK. Swat is 3hk, Fal + SMR are 2hk; Scar and AN-94 is 3HK @ 53 units. The others are tied w/ SMGs at 4hk.
At 123 units all the SMGs are 6hk. At that range, MTAR, M27, Scar, AN-94 are all 4hk. SMR, Fal, Swat are 3hk and the rest are still better than SMGs at 5hk.
At max range some SMGs are faster TTK than ARs but we're talking 180+ units and at that range most SMGs need to burst fire and you can't really hit those theoretical TTKs. The only one I can full auto at range w/ is MP7 which is 0.35s and slower than everything but the AN-94 at max range.