No they are not, Both Madrid and Psg are FFP bound this summer given what they have spent, if pogba have an explosive season there is every chance the price will be matched if their are multiple clubs involved, also pogba is being paid handsomely and living a great life financially, so even If he stays his career path isn't being blocked, this not the case with Maguire after he turns 27.
No one will ever match the price Maguire is being quoted this summer, next summer or even further, Leicester are denying him his career development and financial development when they can easily replace him with half the price the buyer is willing to offer on Maguire, united won't get any top player with his Quality for half the price.