No reason that your set up shouldn't sound great, but it might be improved if you space your speaker apart about the sme distance as it is to your sweet spot, i.e. 8 to 9ft. You might also try crossing the axis of your speakers 3 ft or so in front of the sweet spot. That will give you a much wider sweet spot on the sofa - three people will get some very good soundstage effect not just hearing the speaker closest to them. The toe in will also pretty much eliminate any residual first reflections off the adjacent side wall.
But its all trial and error - have fun.
But its all trial and error - have fun.