Ibra is probably one of the greatest talents to ever play the game, just look at his club history Malmo, Ajax, Juventus, Inter Milan, Barcelona, Milan and PSG. At every club, he has scored a goal every two games (apart from Juve). He has won the Dutch title (2 times), Italian title (6 times), La Liga, French Ligue 1 ( 4 times), Dutch Cup twice, Italian Cup 3 times, French Cup 3 times, along with the Super cup and world club cup. He has played in 4 Champions League quarter-finals and one semi-final.
Defoe, on the other hand, has played for Bournemouth, West Ham, Tottenham, Portsmouth, Toronto and Sunderland. Through his career, he averages a goal every 2.5 games, but at the height of it at the best clubs, it's worse. He has only every played six games in the Champions League. He has never won a trophy in his career.
So not sure how you can even possibly compare the two. Especially considering the far different player pools the two countries you mentioned pick from. You are hard pressed to name another Swedish striker whereas England have a host of club top scorers to pick from.