Interesting thoughts Al. A couple of reasons I picked the players I did
Brett Stewart on the wing. Brett was a speedster and probably the second best player at finding the try line after Irvine. In fact in Irvine's career, Ken averaged 0.9 tries per game. Stewart averaged 0.7, but prior to 2009 when all the trouble started he was averaging 0.82 tries per game. Compare that with other players you mentioned. O'Connor 0.46, Mooney 0.5, Boustead 0.39, Shearer 0.4. People rave about Slater but his average is only 0.59. A winger needs to find the try line. Add to that Stewart's defence and other skills and I think he would have been the second best wing man in the game after Irvine, had he had played there.
Crucher over Watmough. Crusher certainly knew how to shatter a defence line. I just thought Watmough had a better all round game including better defence. Day and Veivers I recall well. Good players of International standard. Worth a thought as was Roberts. Kosef unfortunately never reached his potential because of injury I felt
I have to admit to being a Cliff Lyons fan, and consider him the second best player I've seen play for Manly. But Alan Thompson was also outstanding and they both played a similar number of tests and were in winning grand finals. I guess for me what tips it is Lyons twice won the Dally M award and once the Clive Churchill Award. He also assisted Menzies to become the great try socring freak he became. As for Wally O'Connell, he only played 2 seasons (34 games) with Manly. If you consider him you cant then knock out Irvine who was with Manly for three seasons and 60 games. Wally was apparenty brilliant. I never had the chance to see him. He would have to be pretty special in my mind to beat Cliffy though.
But in the end its all about personal perceptions isnt it? I can certainly see why you identified the players you did. Manly have been blessed with great players in its history.