"several rationales" is correct and usable in written English
You can use it when referring to several reasons or justifications for an action or decision. For example, "The committee discussed several rationales for approving the new policy."
The Obama Administration has offered several rationales supporting the constitutionality of the law.
Democrats offer several rationales for why they are not breaking through with their legislative successes.
Former and current students at Stuyvesant High School say lower-level cheating is part of the culture, and students employ several rationales for choosing to be dishonest.
Justice David H. Souter's majority opinion repeatedly emphasized the need for "deference to legislative choice" in campaign finance, and endorsed several rationales for the close regulation of corporate political money in particular.
But Loomer provided several rationales for her actions: that she had merely used words, whereas the left engages in actual violence; that she felt it was her patriotic duty to stop the play, which was "a form of terrorism" that would "bring us closer to civil war"; that the Public Theatre is "aligned with ISIS, politically".
The aversion to alternative styles was accompanied by several rationales.
Recent advances made in genome sequencing have accelerated the construction of genome-scale metabolic networks, which in turn have led to the growth of several rationale-based strain optimization protocols (Burgard et al., 2003; Kim et al., 2011; Maia et al., 2012; Pharkya et al., 2004; Yang et al., 2011).
There are several different rationales for time-limited subsidies.
Though several potential rationales have been proposed to explain these differences in illness course and comorbidities, including varying levels of psychosocial stress in childhood and differential migration patterns according to genetic vulnerability of affective disorders, no single theory has been shown to possess significantly greater validity than others (Post et al. 2014).
Several therapeutic rationales exist which aim to correct known molecular Ca2+ signaling abnormalities in HF as summarized in Table 2.
Several biologic rationales have been postulated for possible adverse associations between higher vitamin D status and increased cancer risk, including induction of phase I metabolizing enzymes under certain conditions (19), which may be relevant in some populations.
