Comcast was first out of the races with third quarter results among the US big hitters, so with no AT&T, Dish Network, Altice USA or Charter Communications to compare it with, where does the cable TV giant stand? To no great shock, the answer is certainly not on sturdy ground as far as cable TV is concerned. Comcast experienced another sharp video subscriber decline in Q3, losing 238,000 subscribers to bring its footprint abruptly down to 24.1 million, adding to the hefty 224,000 subs loss in Q2. At approaching a quarter of a million cord cutters a quarter, Comcast is on track to churn out enough subs to slide below 20 million by 2023. At the current downward curve and…