I think there is a lot about personal physiology at play here. I could do the 2.7k Cooper easily - I'd have a good 200-300m extra in the locker without busting a gut. In contrast, I've had to work hard to get ready for the new L3 test & although I was never in danger of not getting to the end yesterday, it definitely hurt !Yes, I've practised the L3 test, but only in a crude manner. I'd reserve judgement on their test until such time that I run it properly on a running track. I'm mindful that it's significantly more difficult, although I suspect I'd still find it easier than the Cooper
Like I say, maybe 2.6K has always been slightly too challenging for Level 4. With a shortage of Refs, the last thing the FA could do, is set the bar too high for L4s under the new format. Perhaps they'll tweak it next year. I reckon many of us could've done another 40 reps yesterday back-to-back... I may even try that in pre-season just out of interest; not a lot different from running a 10K in equivalent overall time (52 mins)?
I also know at least 3 level 3s who stepped down last season because they could do the Cooper, but not the new test. As you say though, there may well be people for whom it works the other way around.