12th man, you were perhaps being a bit too selective when you chose only to quote the words "Yogi with a team that reached Europe and won the Scottish Cup, was a result of the quality of the players he recruited " whereas if you had instead chosen to extend your quote to the entire sentence "It has become increasingly apparent that much of the success of the Butcher era, which had enough momentum to provide Yogi with a team that reached Europe and won the Scottish Cup, was a result of the quality of the players he recruited" a different interpretation may have emerged.
Now I do agree that there would have been no scope at all for ambiguity at all if I had said "the players which Butcher recruited" or "the players which he (Butcher) recruited" . In hindsight that would have been a better way of putting it since the last named person before the "he" is indeed "Yogi" rather than "Butcher". But, given that "Yogi" is in a separate clause interpolated into the statement linking "Butcher" and "he", and that the full sentence doesn't seem as ambiguous as the part of it you selected.... I maybe just got away with it!
So to avoid any ambiguity - in my view, much of the success at ICT of John Hughes, whose own signings were less than impressive, originated from players recruited by Terry Butcher.