It's interesting reading these accounts, but I think a note of caution is always warranted.
There's a temptation, even at lower levels, to look back on blokes you face when you're younger as being rapid compared with blokes you faced or watched later on, but it ain't necessarily so. To look at it from the perspective of even a very average player like me, I faced blokes in our A grade comp when I first started playing and opening the batting who I thought were really quick (and tbf they weren't slouches, but they seemed full on quick at the time).
When I was about 30 and been playing for ten years, I faced a bloke who'd just come into the comp, and when he measured out his run up my mate said to me "This bloke is pretty sharp, but he sprays it around". He was right - he was sharp but didn't seem overly express or anything and never got me out for the few seasons I played against him, but I have no doubt he was faster than the blokes I faced when I was younger. He just didn't seem it, because you're a bit older and know your game a bit better, and like these observers from decades earlier, you don't have the benefit of radar guns to confirm or deny your impressions.
Anyway, the blokes I faced when I was younger and who frightened me had a bit about them, but for whatever reasons never kicked on. The other bloke who I played with a bit of respect but who didn't really put the fear of God into me opened the bowling for Australia.
Perceptions are often deceptive.