It's a comedy panel show. A penny to the pound he was fed who'd be his "Feel the Sportsman" by the production team prior to taping. Panel shows are meticulously planned and actually have pretty much no spontaneity whatsoever, despite the "off the cuff" on-air presentation. Adam Buxton and others who have appeared on them have written blogs on it.
You're right on Giant Haystacks being very well known in the mainstream, it's a dodgy source though is that.
Anecdotally, the elder gents in the pub when they mention the old WoS talents are likely to name Daddy, Stacks, McManus, Les Kellet, Sid Cooper, Catweazle and Jim Breaks.