I mean Rondon 100% was and let's not kid ourselves there is reason we sold Tony to a League 1 club at the time, Armstrong seems very Dwight Gayle in that he's great in the Championship but can't cut it in the Premier League, and Mitrovic has has 4/5 seasons in the too division and never really made an impression.
It's completely understandable why in isolation each of them players left. It's not Rafa's fault he had to consistently pick the 5/6 player on his list each time.