Never let it be said that recent deprivation and downsizing have stripped Glasgow's football clubs of their gallusness.

The rest of the planet must look with wonder at the fact that a city of fewer than a million citizens has the most successful football club in the world on one side of the river which splits it, and potentially the biggest football club in the world on the other.

That's some going, Glasgow.

It is Rangers, of course, who occasionally market themselves as the most successful outfit football has ever seen. This causes predictable agitation for those who insist it cannot possibly be true of a club which is dead/new/two years old etc. But a point of contention even some Rangers supporters would agree with is the questionable idea that winning skiploads of trophies in Scotland carries greater weight than, say, Real Madrid lifting ten European Cups.

Maybe no other club matched the volume of silverware won by Rangers between 1891 and 2011 - their first major trophy and their last - but few outwith their fanbase would see any credibility in the idea that they have been higher achievers than serial international tournament winners like Real, Barcelona, Bayern Munich, Liverpool or Ajax (to name European contenders alone).

Celtic's claim on some global pre-eminence came from their chief executive, Peter Lawwell, at the club's annual meeting on Friday. "If Celtic played in an environment in which the media values were similar to those available in the English Premier League we'd be the biggest club in the world, no doubt," he said. "If you go back 25 years and compare us to Man United before the media and revenue boom there probably wasn't much in it."

This isn't the sort of stuff that's worth getting worked up about, but it's an entertaining catalyst for knockabout argument. Lawwell was right to refer to a pre-English Premier League era for a sense of Celtic and United's fundamentals - before the distorting transformation of the English game through unimaginably lucrative television deals and globalisation - but the history books do not back up his assessment of the club's respective status.

At no point could it be convincingly argued that Celtic were a "bigger" club than United, even allowing for the unscientific aspects of what that phrase even means. In the decades when a club's size was more accurately reflected by its actual attendances (and its international appeal was far less relevant) United always attracted significantly bigger numbers.

In 1966-67, when Celtic announced themselves to a world audience by winning every trophy they contested including the European Cup, their average league attendance was 31,082. United's was 53,895.

In 1974-75, when Celtic were going for ten-in-a-row, they averaged 22,775 and a relegated United averaged 48,388 in England's old second division.

In 1991-92, the last season before English football was turbo-charged by BSkyB and even the remotest sense of parity could be claimed for the major clubs on either side of the border, Celtic averaged 25,086 and United 44,985.

The inevitable flow of talent from Parkhead to Old Trafford over the years - Paddy Crerand, Lou Macari, Brian McClair, all before United's brand exploded across the world - gives further evidence of the natural order.

Lawwell's view is that if Celtic were in the Barclays Premier League themselves they would grow exponentially and eventually be a match for the real elite. "Our story is unique, it's rich, and it's the best," he said at their agm. "We have a potential fanbase with Scots and Irish diaspora around the world."

But even if it could monopolise the allegiance of that diaspora it would not, on its own, be enough to ever establish Celtic as the biggest in the world. Celtic's origins, the Lisbon Lions, the fervour of Parkhead crowds and even the green-and-white hoops make for a powerful narrative which is seductive to millions of Scots/Irish heritage. But what do young 21st-century markets in Asia, Africa or South America care about any of that? Not even two decades of consistent prominence and success in the most globally exposed football platform of them all have taken the modern Chelsea close to being the world's biggest club.

Of course Celtic's support is vast. Of course they are recognised as a distinctive, substantial club. Of course they can draw on huge numbers in North America, the bedrock of their international support. But so can United, whose friendly against Real Madrid three months ago set a record for a football match in the USA when 109,000 filled the Michigan Stadium. And, crucially United, Liverpool, Arsenal and Chelsea all have a real presence in Asia, Africa and South America which puts them years ahead of recently-emerging forces like Manchester City and PSG, let alone Celtic.

Lawwell's view has given us something to talk about. No-one can say with any certainty how big Celtic would become if they could ever realise their ambition of getting their hands on that Barclays Premier League loot. But, by some measures, they are barely on the radar at all and even Manchester United themselves are eclipsed.

On Facebook, United have 61m followers worldwide. That seems a staggering number until you learn that Real Madrid have 77.8m and Barcelona even more, 79m. Celtic have 1.2m.