Barry Richards said that his pace was quite
gentle compared to today's bowlers (and even contemporaries), though - he said his greatest gift was his swing.
His illness began in 1980, after his return from England (including his long stint in the Lancashire League), when he ate a packet of peanuts and then endured a blockage of the bowel. He then became a medical guinea-pig, having his liver cut into pieces, amongst other things.
I was also under the impression that Caddick was a bit quicker than Fleming, but I could be wrong. Maybe it's because Caddick cantered to the wicket and fired it down, whilst Fleming's run-up was comparatively gentle and he wasn't really striving for pace.
Lee was excellent early on (7 Tests), was mostly poor from 2001-2005 with a couple of good Tests, was good to OK in 2005/06, inconsistent in 2006/07, excellent in 2007/08 and a has-been by 2008/09, when it started to become clear that his body could not hold up anymore. He could therefore be said to be over the hill. That is significiant in Lee's case, because he averaged nearly 50. If Hawke was made to bowl under such conditions, he may have ended with a much higher average.
Well, he was excellent whenever England showed themselves early on. He had a very good home series against Pakistan too. From then on, he faded (with the notable exception of a home series against WI), sometimes doing even worse than Lee against some fairly crappy opponents (England in 1985 only looked good compared to AUS, who were utter ****). Whatever else can be said about Lee, even when he was bowling poorly, he did manage to take wickets against lower-end Test-class teams. Lawson then experienced a renaissance against England in 1989, but that was his last hurrah. After that, he was more or less over the hill as a Test bowler.
It is hard to say who is better - Lawson had to lead the attack for longer and never did have bowlers or batsmen as good as what Lee had beside him, but got to bowl on friendlier decks against generally less resistant tailenders. He still had some very good (even world-class, where Lillee's concerned) bowlers alongside him. I don't think Len Pascoe played alongside him - much of his career was spent in WSC.