I think Force India would rather have Sergio over having to develop a driver from zero when instead you can get a guy who has showed speed and now counts with a year of Development from McLaren might I remind you that Perez is 23 and has 3 seasons of F1 experience so in FIs perspective it's better to take Perez then Magg.. I think FI simply didn't even consider the idea of taking in Magg because they try to always have the best possible drivers period. Rookie drivers no matter how much a team like McLaren or Ferrari tell you are not going to be taken up by a team like Force India who doesn't go for pay drivers Milaj idk how to spell his name said it himself we don't do business in Mexico and while there might be opportunities for Marketing we got him and he is being paid.. For his services as the fastest possible driver available..
Simply put Hulk and Perez were the best they could get so they got them..