My room is almost identical in size as yours in all dimensions.
I think it depends how much you’re willing to treat your room. I’m using my room as a music/2-ch room, an Atmos home theater room (though all 9 speakers are in-wall or in-ceiling), as well as storing all my media in the room (>1000 records, similar # of CDs). So I don’t have a lot of room to install treatments. Record racks, wall cabinets to store CDs, or gear furniture line most of my walls and go very near if not all the way to the corners. So big bass traps just wasn’t going to happen.
I just have a couple of 4x2ft acoustic panels near the first reflection point.
I tried to use Aerial Acoustics Model 7B’s which I used and loved in a bigger space - the bass was really way too much. Also tried some Monitor Audio and Sonus Faber towers and at that point they were also too much. This was all using a standard preamp and amp and trying to move my listening position forward and back to find a sweet spot.
I ended up going with bookshelf speakers and 2 sealed subs to help smooth out the bass response in the room. I also moved away from a standard preamp and went with a miniDSP Flex as my preamp because it could do DSP/room EQ with its 10 bands of PEQ per channel. Now my response is quite good and everything sounds balanced in my listening spot.
Had I gone with the Flex to start, perhaps I could have gotten away with staying with the Aerials - I’ll never know.
Just moving to bookshelf speakers and 1 sub to start with, along with an open mind on listening position, got me to a livable state, even though it still measured not very great. It wasn’t perfect, but it was fine.
Because it’s my dedicated room, I did want more than fine which is why I got a second sub and went the DSP/room correction route.
I think, blank slate, if you could find a way to design and treat your room acoustically so 80+% of your room issues were addressed, then you may be able to get by with just speaker setup and listening position tweaks to get to a nice outcome.
But if you can’t or prefer not to treat your room, my feeling is getting to a really nice outcome sonically is really difficult to do with larger speakers. With smaller speakers and a sub or two, probably doable, but just from my recent experience, either room treatments or some kind of DSP is what it would take in most situations.