This Motherwell's Greatest is a great piece of fun, as we know it can never be definitive. Personally, I would have to include anyone who played in the league and cup-winning teams (including LC) because they proved they achieved at the top level in their era. There can't be anyone still alive who saw the league champions, although I worked with an old guy who had. Stevenson and Ferrier were sought after by several English clubs in a blank-cheque fashion (notably Arsenal) and Willie McFadyen scored an unsurpassed record 52 goals when we won the league.
My Dear Old Dad would tease me by saying John McMenemy was a haddie who missed more than he scored, but then my father was an Accies fan who I don't think grasped JM's main function, which, as an IR, was to put it on a plate for WMcF. He also boasted he was the happiest man in Motherwell as he worked an extra time-and-a-half shift as a mechanic in Taggart's garage next to FP as Clyde crushed us 0-4 in the 1939 Cup Final.
If we include all the trophy-winning teams, it would be all down to the personal opinion of supporters who have seen the younger generations of MFC players, which is where the fun comes in.
Faîtes vos jeux and Tongs ya bass!