It has to be less powerfull because the room side to fill with is quite difficult with some bass frequency accumulation at the ceiling level. I am applying some room correction though with Roon’s DSP engine
I think it’s really important to get your fist sub dialed in before deciding to go with a second. Minimize the bass peaks because those will force you to set your overall sub volume too low.
Consider bass traps like Gik’s corner or soffit traps.
Roon is great but it won't work when you have 2 subs. You'll need a miniDSP like device to give you separate control over each sub.
Look at the AM Acoustics room mode simulator and try to place your sub, speakers and listening location out of the lowest bands.