As is Colin Hutton, who will be a surprise to many but not to some who were watching in the 50's.

Billy Batten, Johnny Whiteley, Clive Sullivan.

Mick crane,swain,whiteley,norton.

From my time of watching

Swain, Horne, Whiting

Whiting is definitely not a legend, wouldn't even say Horne is one.

Legend doesn't mean greatest player or the most medals, it means players of integrity, loyalty, endeavor when the chips are down. It means class, respect and honour.
it's those whom have garnered the ultimate respect from both fans, players and coaches, i guess some of the latter generation names bandied around like Swain and kearney etc deserve recognition for what they did to help the club to success, does that make them legends in their own right above those that gave their all to the club often without reward or during barren times, IMHO, no it doesn't.
it's always a subjective list as to whom are legends but this is mine
Jack Harrison VC
Bob Taylor
Harold Bowman
Ned Rodgers
Joe Oliver
Johnny Whiteley MBE
Tommy Harris
Alf Macklin
Mick Scott
Clive Sullivan
Steve Norton
Richard Horne

In the time I've been watching I'd only really label Swain as a legend. Couple of others come close but Swain was the real deal.

Best 2 players I've seen play for us are knocker and sterling . If your looking for 2 legends I'd say knocker and Whiteley

For my third I would add John Whiteley to Batten and Francis.

Seeing both Whiteley and Norton would put Whiteley a street ahead of Norton who was a disappointment for me when he was out here playing for Gt Britain and Manly. He was not a patch on the other ex-Castleford player Mal Reilly he replaced and Phil Lowe who played in the same Manly team was the forward I liked to watch.

Having said that I can support him as one of the 20 legends selected in the book.

Should be Joe Oliver the man Old Faithfull is based on and John Whiteley if your doing a thesis
Could add Sammy Evans to that not that he's an actual HullFC Legend but is a the only player to play for us ,them and City