Unless you’re setup is in an aircraft hanger, that’s crazy overkill, but you do you.
This too-clever-by-half comment is not that clever. It reflects a misunderstanding of why multiple subs are helpful. It’s about the room’s acoustics. It depends a lot on the room (see comment in next paragraph about measuring).
Having three subwoofers isn’t about more bass, but achieving a more articulate and even bass response throughout your room. A single subwoofer creates "hot spots" and "nulls," leading to muddy or boomy or weak bass. Multiple, strategically placed subwoofers smooth out these peaks and dips, providing tight, detailed, and clear bass across a wider listening area. You should be prepared to put them where the sound is best, not where they "look good." The goal is audio balance not visual symmetry or prettiness.
You will need to learn a little. Measurement and Digital Signal Processing (DSP) are essential. Using a microphone (UMik) and software (REW, for example) can help measure your room to reveal problem areas. DSP then allows precise equalization and time alignment for each subwoofer, ensuring they work harmoniously.
I recommend Rythmik sealed subs as better options than REL, e.g. They are more flexible (adjustable phase, for one) and more economical.