This thread is hilarious, so much them and us.
The wider arc you need to more time you need. If I can 'nip around' great, makes it easy for everyone and causes no one any problems or delays; I always give plenty of space to bikes.
If I am in a 60 however zone and I need to get around a bike doing 10mph, then the opportunity for said lycra wearers to become an obstruction is greater than if they were riding single file. To have 2 bikes side by side in such a situation is bad road craft, so these arguments need to be predicated on circumstance, not drawings and definitions in the highway code as without circumstance they add sod all to the debate in most cases.
I ride and I drive and I find bad road craft in both forms and hell, am probably guilty of it myself now and again. These threads ALWAYS dig and dig and dig and dig until the core point is lost and people then try to score points with drawings, wiki extracts and other such 'content'. I have no idea how the OP was driving or how the bikes were riding. I have often come across bikes down my lane side by side, once stopped drinking water in the MIDDLE of the road as a group because, well, it's a country lane, no one will come down here over this blind hill at 40mph....even though it's 60mph lane. Often they don't hear me, but I don't bib, well unless they are 'choosing' not to notice me, but wait for them to be aware and in most cases they move into single file. When then don't, when the become an obstruction and slow down the traffic for no good reason than belligerence then need a metaphorical slap, even if it's a horn in my opinion and if they get angry at that, **** em, but I wouldn't need a thread to debate the merits.