If a goalscorer' goal tally had more to do with his teammates than his own abilities, you'd have dozens upon dozens of players scoring 40 goals a season in all of the teams that produce a great amount of quality attacking plays. In the end, it's always about team work and everyone contributing... There's a reason that in the 21st century, only Ronaldo, Messi, Ibra, Lewa, Halaand and another set of 5-10 players were/are able to score 40/50 most seasons. If it was like you described, you'd have 100 of those players in the last 25 years. Of course that when these players finish a play with a goal, it's not fair to pretend they scored themselves alone, but it's also not fair to say they lack (special) ability and are riding on others' work.
Confidence between teammates also goes a long way. There were several Real Madrid players saying in interviews (Kroos, etc) they knew they could give it their all on the pitch on the roles they were assigned, because up front they had blind confidence Ronaldo could make their hard work payoff any time, in any situation.