Not always. Although we certainly find Gemaras that seek to harmonize opinions of a single person into one Shitta, later on it gets different.
In Iggros Moshe (I need to find where) there was a question about a child who learned how to lain a parsha for his Bar Mitzvah, but close to the date, they realized that they had miscalculated his birthday, and his bar mitzvah would only be after that parsha. The question was could he lain anyway.
In the responsum, Rav Moshe Feinstein goes at length about how reading the Torah has to be from someone Bar Mitzva specifically, otherwise the listeners aren't really fulfilling the obligation. However, he quotes earlier Achronim who disagree, seems to be unable to justify their opinion, but yet still lets it go for this case and allows the boy to lain.
This would seem to come from rather than following his own Shitta, recognizing that someone else could rely on a different Shitta and deferring to it - even at the expense of everyone else in Shul.
All of this would seem to apply in a case of need, and really under the recognition that there is no single psak for all Klal Yisroel today. Obviously he would have preferred to follow his Shitta.
I can't imagine such an exception applying to Hashkafa, or why it would need to. Although I could imagine cases where two different suggias suggest different conclusion, and holding them both simultaneously seems, or is contradictory. But that is more a case of having an unresolved paradox, if it is even possible to have a shitta which is fully self consistent.