It wasn't just the Sun & Talksport. There were other agencies reporting the same. Are you saying none of these were credible too.
I think most neutrals would say Villa, Leeds & Sunderland would be averaging higher attendances than you if they were in your position. There would likely be others. It can't be said as fact as you are the only state funded club.
I'm not sure how you are able to talk on behalf of most neutrals but so be it.
Its possible that without stadium constraints that those three clubs could average more than City if they were in identical circumstances, however, as we will never know its probably more prudent to look at actual and factual attendance figures. From 1970 for all clubs.
Leeds first, for whatever reason the size of Leeds as a club is grossly overstated on this site. Even though Elland Road held over 50,000 for a lot of this period Leeds have never had an average attendance over 40k, in fact I don't think they have sold out Ellland Road once in the last twelve years. If we look at Leeds last success, the year they won the league they had an average of 29440, City, finishing 5th averaged a mere 1800 less. So Leeds, in a season of unprecedented glory averaged only slightly higher than City. Its also worth noting that Leeds' highest ever crowd is just 57k, City's is 85k. Leeds have historically had worse crowds than City and there is no evidence of that changing.
Aston Villa, surely one of the most fickle fan bases in the UK. The best comparison is the seasons between City leaving Maine Road and the post-takeover success. During this period Villa and City were broadly similar in league positions (around mid-table), yet City's attendances were higher than Villas every single season, on a couple of occasions City's average was over 8k better. Some of the difference was down to the Etihad being slightly better but again there is no evidence of Villa's actual crowds being larger, never mind significantly larger. They definitely have the fan base and catchment area to draw much larger crowds. How much bigger, who knows. Lets not forget that City could also draw far more than they currently do. Just wait till the stadium expansion takes place to see.
Finally, Sunderland. I've got a lot of time for Sunderland and think their support is excellent. Current attendances though show you that their hardcore support is around the 20k mark. Its hard to compare (I don't know Roker's capacity for the last few years) other than to say that City's crowds are usually larger, sometimes much larger. I would also suspect that because of the club's geographical position (ie a small town in close proximity to Newcastle and Middlesbrough) that they couldn't go much higher than the current 48k capacity at the SoL.
So, in my opinion, based on actual facts, I disagree that the three clubs you mention would be drawing higher crowds were they in the same position as City.