Medieval Christian thinkers were sometimes aware of the tensions between Aristotle’s ideal of magnanimity and Christian virtues like humility. According to Tobias Hoffmann’s essay in Virtue Ethics in the Middle Ages: Commentaries on Aristotle’s Nicomachean Ethics, 1200-1500 (Brill’s Studies in Intellectual History) 
According to Hoffmann, “In Albert’s understanding, there is no opposition between the Aristotelian view of magnanimity and virtues of biblical inspiration” and he makes an effort to bring “Aristotelian magnanimity into line with other virtues, above all with gratitude and humility.” In contrast to his work on Aristotle’s physics and metaphysics, Albert’s treatment of ethics shows his strong affinities for the Aristotelian viewpoint (p. 109).
He finds nineteen traits in Aristotle’s portrait of the magnanimous man and gives particular attention to three that might be considered vices: ingratitude, inactivity, and laziness. He disposes of the last two rather by smudging the meaning of the words:
“The magnanimous are inactive with regard to mean and base actions, since they prefer to do great things. Their laziness means that they are not precipitous, but premeditate their action carefully in order to avoid doing something unworthy.” Ingratitude won’t be disposed of so easily. Albert recognizes that “Aristotle’s magnanimous persons remember what good they have done to others, but not the good they have received; they like to hear about the latter but not about the former,” and he cites Seneca and Cicero to counter this view. In the end he gives this inadequate solution: “someone is ungrateful who does not return the good things received. Conversely, Aristotle’s magnanimous man is exemplary in matters of giving and receiving: he returns more than the good received. Albert adds that he tries to return the good quickly, so that he is not in the other’s debt.” Despite appearances, then, the magnanimous man is not in fact ungrateful after all (p. 114).
In the ST (II-II, q. 129), Thomas also raises objections to Aristotelian magnanimity. Hoffmann summarizes: “Five apparently blameworthy traits of Aristotle’s portrait are presented in the fifth objection: ‘First, he is forgetful of the benefactors; second, he is idle and slow of action; third, he employs irony towards the many; fourth, he is unable to live with another; fifth, he rather possesses unproductive than fruitful things.’ In his reply, Thomas does not say that these characteristics are not blameworthy as such. But ‘insofar as they characterize the magnanimous person, they are not blameworthy, but rather exceedingly praiseworthy.’” Like Albert, Thomas turns the magnanimous man’s apparent ingratitude into excessive gratitude: “that he does not remember his benefactors means that he does not like to receive gifts or favors ( beneficia ) without repaying them with greater returns.”
Hoffmann concludes that “Apparently Thomas did not think there was a true difficulty here. Interestingly, his discussion of gratitude and ingratitude in questions 106–107 of the Secunda secundae does not contain a single reference to the magnanimous person’s forgetfulness of favors received, although Thomas could have easily integrated such a discussion, if only into the objections” (pp. 125-6).